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Posted to commits@hbase.apache.org by gi...@apache.org on 2017/08/10 22:29:55 UTC
[05/33] hbase-site git commit: Published site at
82d554e3783372cc6b05489452c815b57c06f6cd.
http://git-wip-us.apache.org/repos/asf/hbase-site/blob/99c53df1/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/snapshot/FlushSnapshotSubprocedure.RegionSnapshotTask.html
----------------------------------------------------------------------
diff --git a/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/snapshot/FlushSnapshotSubprocedure.RegionSnapshotTask.html b/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/snapshot/FlushSnapshotSubprocedure.RegionSnapshotTask.html
index c73100f..b3c1730 100644
--- a/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/snapshot/FlushSnapshotSubprocedure.RegionSnapshotTask.html
+++ b/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/snapshot/FlushSnapshotSubprocedure.RegionSnapshotTask.html
@@ -41,181 +41,190 @@
<span class="sourceLineNo">033</span>import org.apache.hadoop.hbase.regionserver.HRegion;<a name="line.33"></a>
<span class="sourceLineNo">034</span>import org.apache.hadoop.hbase.regionserver.Region;<a name="line.34"></a>
<span class="sourceLineNo">035</span>import org.apache.hadoop.hbase.regionserver.Region.FlushResult;<a name="line.35"></a>
-<span class="sourceLineNo">036</span>import org.apache.hadoop.hbase.regionserver.snapshot.RegionServerSnapshotManager.SnapshotSubprocedurePool;<a name="line.36"></a>
-<span class="sourceLineNo">037</span>import org.apache.hadoop.hbase.shaded.protobuf.generated.SnapshotProtos.SnapshotDescription;<a name="line.37"></a>
-<span class="sourceLineNo">038</span>import org.apache.hadoop.hbase.snapshot.ClientSnapshotDescriptionUtils;<a name="line.38"></a>
-<span class="sourceLineNo">039</span><a name="line.39"></a>
-<span class="sourceLineNo">040</span>/**<a name="line.40"></a>
-<span class="sourceLineNo">041</span> * This online snapshot implementation uses the distributed procedure framework to force a<a name="line.41"></a>
-<span class="sourceLineNo">042</span> * store flush and then records the hfiles. Its enter stage does nothing. Its leave stage then<a name="line.42"></a>
-<span class="sourceLineNo">043</span> * flushes the memstore, builds the region server's snapshot manifest from its hfiles list, and<a name="line.43"></a>
-<span class="sourceLineNo">044</span> * copies .regioninfos into the snapshot working directory. At the master side, there is an atomic<a name="line.44"></a>
-<span class="sourceLineNo">045</span> * rename of the working dir into the proper snapshot directory.<a name="line.45"></a>
-<span class="sourceLineNo">046</span> */<a name="line.46"></a>
-<span class="sourceLineNo">047</span>@InterfaceAudience.Private<a name="line.47"></a>
-<span class="sourceLineNo">048</span>@InterfaceStability.Unstable<a name="line.48"></a>
-<span class="sourceLineNo">049</span>public class FlushSnapshotSubprocedure extends Subprocedure {<a name="line.49"></a>
-<span class="sourceLineNo">050</span> private static final Log LOG = LogFactory.getLog(FlushSnapshotSubprocedure.class);<a name="line.50"></a>
-<span class="sourceLineNo">051</span><a name="line.51"></a>
-<span class="sourceLineNo">052</span> private final List<Region> regions;<a name="line.52"></a>
-<span class="sourceLineNo">053</span> private final SnapshotDescription snapshot;<a name="line.53"></a>
-<span class="sourceLineNo">054</span> private final SnapshotSubprocedurePool taskManager;<a name="line.54"></a>
-<span class="sourceLineNo">055</span> private boolean snapshotSkipFlush = false;<a name="line.55"></a>
-<span class="sourceLineNo">056</span><a name="line.56"></a>
-<span class="sourceLineNo">057</span> // the maximum number of attempts we flush<a name="line.57"></a>
-<span class="sourceLineNo">058</span> final static int MAX_RETRIES = 3;<a name="line.58"></a>
-<span class="sourceLineNo">059</span><a name="line.59"></a>
-<span class="sourceLineNo">060</span> public FlushSnapshotSubprocedure(ProcedureMember member,<a name="line.60"></a>
-<span class="sourceLineNo">061</span> ForeignExceptionDispatcher errorListener, long wakeFrequency, long timeout,<a name="line.61"></a>
-<span class="sourceLineNo">062</span> List<Region> regions, SnapshotDescription snapshot,<a name="line.62"></a>
-<span class="sourceLineNo">063</span> SnapshotSubprocedurePool taskManager) {<a name="line.63"></a>
-<span class="sourceLineNo">064</span> super(member, snapshot.getName(), errorListener, wakeFrequency, timeout);<a name="line.64"></a>
-<span class="sourceLineNo">065</span> this.snapshot = snapshot;<a name="line.65"></a>
-<span class="sourceLineNo">066</span><a name="line.66"></a>
-<span class="sourceLineNo">067</span> if (this.snapshot.getType() == SnapshotDescription.Type.SKIPFLUSH) {<a name="line.67"></a>
-<span class="sourceLineNo">068</span> snapshotSkipFlush = true;<a name="line.68"></a>
-<span class="sourceLineNo">069</span> }<a name="line.69"></a>
-<span class="sourceLineNo">070</span> this.regions = regions;<a name="line.70"></a>
-<span class="sourceLineNo">071</span> this.taskManager = taskManager;<a name="line.71"></a>
-<span class="sourceLineNo">072</span> }<a name="line.72"></a>
-<span class="sourceLineNo">073</span><a name="line.73"></a>
-<span class="sourceLineNo">074</span> /**<a name="line.74"></a>
-<span class="sourceLineNo">075</span> * Callable for adding files to snapshot manifest working dir. Ready for multithreading.<a name="line.75"></a>
-<span class="sourceLineNo">076</span> */<a name="line.76"></a>
-<span class="sourceLineNo">077</span> private class RegionSnapshotTask implements Callable<Void> {<a name="line.77"></a>
-<span class="sourceLineNo">078</span> Region region;<a name="line.78"></a>
-<span class="sourceLineNo">079</span> RegionSnapshotTask(Region region) {<a name="line.79"></a>
-<span class="sourceLineNo">080</span> this.region = region;<a name="line.80"></a>
-<span class="sourceLineNo">081</span> }<a name="line.81"></a>
-<span class="sourceLineNo">082</span><a name="line.82"></a>
-<span class="sourceLineNo">083</span> @Override<a name="line.83"></a>
-<span class="sourceLineNo">084</span> public Void call() throws Exception {<a name="line.84"></a>
-<span class="sourceLineNo">085</span> // Taking the region read lock prevents the individual region from being closed while a<a name="line.85"></a>
-<span class="sourceLineNo">086</span> // snapshot is in progress. This is helpful but not sufficient for preventing races with<a name="line.86"></a>
-<span class="sourceLineNo">087</span> // snapshots that involve multiple regions and regionservers. It is still possible to have<a name="line.87"></a>
-<span class="sourceLineNo">088</span> // an interleaving such that globally regions are missing, so we still need the verification<a name="line.88"></a>
-<span class="sourceLineNo">089</span> // step.<a name="line.89"></a>
-<span class="sourceLineNo">090</span> LOG.debug("Starting region operation on " + region);<a name="line.90"></a>
-<span class="sourceLineNo">091</span> region.startRegionOperation();<a name="line.91"></a>
-<span class="sourceLineNo">092</span> try {<a name="line.92"></a>
-<span class="sourceLineNo">093</span> if (snapshotSkipFlush) {<a name="line.93"></a>
-<span class="sourceLineNo">094</span> /*<a name="line.94"></a>
-<span class="sourceLineNo">095</span> * This is to take an online-snapshot without force a coordinated flush to prevent pause<a name="line.95"></a>
-<span class="sourceLineNo">096</span> * The snapshot type is defined inside the snapshot description. FlushSnapshotSubprocedure<a name="line.96"></a>
-<span class="sourceLineNo">097</span> * should be renamed to distributedSnapshotSubprocedure, and the flush() behavior can be<a name="line.97"></a>
-<span class="sourceLineNo">098</span> * turned on/off based on the flush type.<a name="line.98"></a>
-<span class="sourceLineNo">099</span> * To minimized the code change, class name is not changed.<a name="line.99"></a>
-<span class="sourceLineNo">100</span> */<a name="line.100"></a>
-<span class="sourceLineNo">101</span> LOG.debug("take snapshot without flush memstore first");<a name="line.101"></a>
-<span class="sourceLineNo">102</span> } else {<a name="line.102"></a>
-<span class="sourceLineNo">103</span> LOG.debug("Flush Snapshotting region " + region.toString() + " started...");<a name="line.103"></a>
-<span class="sourceLineNo">104</span> boolean succeeded = false;<a name="line.104"></a>
-<span class="sourceLineNo">105</span> long readPt = region.getReadpoint(IsolationLevel.READ_COMMITTED);<a name="line.105"></a>
-<span class="sourceLineNo">106</span> for (int i = 0; i < MAX_RETRIES; i++) {<a name="line.106"></a>
-<span class="sourceLineNo">107</span> FlushResult res = region.flush(true);<a name="line.107"></a>
-<span class="sourceLineNo">108</span> if (res.getResult() == FlushResult.Result.CANNOT_FLUSH) {<a name="line.108"></a>
-<span class="sourceLineNo">109</span> // CANNOT_FLUSH may mean that a flush is already on-going<a name="line.109"></a>
-<span class="sourceLineNo">110</span> // we need to wait for that flush to complete<a name="line.110"></a>
-<span class="sourceLineNo">111</span> region.waitForFlushes();<a name="line.111"></a>
-<span class="sourceLineNo">112</span> if (region.getMaxFlushedSeqId() >= readPt) {<a name="line.112"></a>
-<span class="sourceLineNo">113</span> // writes at the start of the snapshot have been persisted<a name="line.113"></a>
-<span class="sourceLineNo">114</span> succeeded = true;<a name="line.114"></a>
-<span class="sourceLineNo">115</span> break;<a name="line.115"></a>
-<span class="sourceLineNo">116</span> }<a name="line.116"></a>
-<span class="sourceLineNo">117</span> } else {<a name="line.117"></a>
-<span class="sourceLineNo">118</span> succeeded = true;<a name="line.118"></a>
-<span class="sourceLineNo">119</span> break;<a name="line.119"></a>
-<span class="sourceLineNo">120</span> }<a name="line.120"></a>
-<span class="sourceLineNo">121</span> }<a name="line.121"></a>
-<span class="sourceLineNo">122</span> if (!succeeded) {<a name="line.122"></a>
-<span class="sourceLineNo">123</span> throw new IOException("Unable to complete flush after " + MAX_RETRIES + " attempts");<a name="line.123"></a>
-<span class="sourceLineNo">124</span> }<a name="line.124"></a>
-<span class="sourceLineNo">125</span> }<a name="line.125"></a>
-<span class="sourceLineNo">126</span> ((HRegion)region).addRegionToSnapshot(snapshot, monitor);<a name="line.126"></a>
-<span class="sourceLineNo">127</span> if (snapshotSkipFlush) {<a name="line.127"></a>
-<span class="sourceLineNo">128</span> LOG.debug("... SkipFlush Snapshotting region " + region.toString() + " completed.");<a name="line.128"></a>
-<span class="sourceLineNo">129</span> } else {<a name="line.129"></a>
-<span class="sourceLineNo">130</span> LOG.debug("... Flush Snapshotting region " + region.toString() + " completed.");<a name="line.130"></a>
-<span class="sourceLineNo">131</span> }<a name="line.131"></a>
-<span class="sourceLineNo">132</span> } finally {<a name="line.132"></a>
-<span class="sourceLineNo">133</span> LOG.debug("Closing region operation on " + region);<a name="line.133"></a>
-<span class="sourceLineNo">134</span> region.closeRegionOperation();<a name="line.134"></a>
-<span class="sourceLineNo">135</span> }<a name="line.135"></a>
-<span class="sourceLineNo">136</span> return null;<a name="line.136"></a>
-<span class="sourceLineNo">137</span> }<a name="line.137"></a>
-<span class="sourceLineNo">138</span> }<a name="line.138"></a>
-<span class="sourceLineNo">139</span><a name="line.139"></a>
-<span class="sourceLineNo">140</span> private void flushSnapshot() throws ForeignException {<a name="line.140"></a>
-<span class="sourceLineNo">141</span> if (regions.isEmpty()) {<a name="line.141"></a>
-<span class="sourceLineNo">142</span> // No regions on this RS, we are basically done.<a name="line.142"></a>
-<span class="sourceLineNo">143</span> return;<a name="line.143"></a>
-<span class="sourceLineNo">144</span> }<a name="line.144"></a>
-<span class="sourceLineNo">145</span><a name="line.145"></a>
-<span class="sourceLineNo">146</span> monitor.rethrowException();<a name="line.146"></a>
-<span class="sourceLineNo">147</span><a name="line.147"></a>
-<span class="sourceLineNo">148</span> // assert that the taskManager is empty.<a name="line.148"></a>
-<span class="sourceLineNo">149</span> if (taskManager.hasTasks()) {<a name="line.149"></a>
-<span class="sourceLineNo">150</span> throw new IllegalStateException("Attempting to take snapshot "<a name="line.150"></a>
-<span class="sourceLineNo">151</span> + ClientSnapshotDescriptionUtils.toString(snapshot)<a name="line.151"></a>
-<span class="sourceLineNo">152</span> + " but we currently have outstanding tasks");<a name="line.152"></a>
+<span class="sourceLineNo">036</span>import org.apache.hadoop.hbase.regionserver.Region.Operation;<a name="line.36"></a>
+<span class="sourceLineNo">037</span>import org.apache.hadoop.hbase.regionserver.snapshot.RegionServerSnapshotManager.SnapshotSubprocedurePool;<a name="line.37"></a>
+<span class="sourceLineNo">038</span>import org.apache.hadoop.hbase.shaded.protobuf.generated.SnapshotProtos.SnapshotDescription;<a name="line.38"></a>
+<span class="sourceLineNo">039</span>import org.apache.hadoop.hbase.snapshot.ClientSnapshotDescriptionUtils;<a name="line.39"></a>
+<span class="sourceLineNo">040</span><a name="line.40"></a>
+<span class="sourceLineNo">041</span>/**<a name="line.41"></a>
+<span class="sourceLineNo">042</span> * This online snapshot implementation uses the distributed procedure framework to force a<a name="line.42"></a>
+<span class="sourceLineNo">043</span> * store flush and then records the hfiles. Its enter stage does nothing. Its leave stage then<a name="line.43"></a>
+<span class="sourceLineNo">044</span> * flushes the memstore, builds the region server's snapshot manifest from its hfiles list, and<a name="line.44"></a>
+<span class="sourceLineNo">045</span> * copies .regioninfos into the snapshot working directory. At the master side, there is an atomic<a name="line.45"></a>
+<span class="sourceLineNo">046</span> * rename of the working dir into the proper snapshot directory.<a name="line.46"></a>
+<span class="sourceLineNo">047</span> */<a name="line.47"></a>
+<span class="sourceLineNo">048</span>@InterfaceAudience.Private<a name="line.48"></a>
+<span class="sourceLineNo">049</span>@InterfaceStability.Unstable<a name="line.49"></a>
+<span class="sourceLineNo">050</span>public class FlushSnapshotSubprocedure extends Subprocedure {<a name="line.50"></a>
+<span class="sourceLineNo">051</span> private static final Log LOG = LogFactory.getLog(FlushSnapshotSubprocedure.class);<a name="line.51"></a>
+<span class="sourceLineNo">052</span><a name="line.52"></a>
+<span class="sourceLineNo">053</span> private final List<Region> regions;<a name="line.53"></a>
+<span class="sourceLineNo">054</span> private final SnapshotDescription snapshot;<a name="line.54"></a>
+<span class="sourceLineNo">055</span> private final SnapshotSubprocedurePool taskManager;<a name="line.55"></a>
+<span class="sourceLineNo">056</span> private boolean snapshotSkipFlush = false;<a name="line.56"></a>
+<span class="sourceLineNo">057</span><a name="line.57"></a>
+<span class="sourceLineNo">058</span> // the maximum number of attempts we flush<a name="line.58"></a>
+<span class="sourceLineNo">059</span> final static int MAX_RETRIES = 3;<a name="line.59"></a>
+<span class="sourceLineNo">060</span><a name="line.60"></a>
+<span class="sourceLineNo">061</span> public FlushSnapshotSubprocedure(ProcedureMember member,<a name="line.61"></a>
+<span class="sourceLineNo">062</span> ForeignExceptionDispatcher errorListener, long wakeFrequency, long timeout,<a name="line.62"></a>
+<span class="sourceLineNo">063</span> List<Region> regions, SnapshotDescription snapshot,<a name="line.63"></a>
+<span class="sourceLineNo">064</span> SnapshotSubprocedurePool taskManager) {<a name="line.64"></a>
+<span class="sourceLineNo">065</span> super(member, snapshot.getName(), errorListener, wakeFrequency, timeout);<a name="line.65"></a>
+<span class="sourceLineNo">066</span> this.snapshot = snapshot;<a name="line.66"></a>
+<span class="sourceLineNo">067</span><a name="line.67"></a>
+<span class="sourceLineNo">068</span> if (this.snapshot.getType() == SnapshotDescription.Type.SKIPFLUSH) {<a name="line.68"></a>
+<span class="sourceLineNo">069</span> snapshotSkipFlush = true;<a name="line.69"></a>
+<span class="sourceLineNo">070</span> }<a name="line.70"></a>
+<span class="sourceLineNo">071</span> this.regions = regions;<a name="line.71"></a>
+<span class="sourceLineNo">072</span> this.taskManager = taskManager;<a name="line.72"></a>
+<span class="sourceLineNo">073</span> }<a name="line.73"></a>
+<span class="sourceLineNo">074</span><a name="line.74"></a>
+<span class="sourceLineNo">075</span> /**<a name="line.75"></a>
+<span class="sourceLineNo">076</span> * Callable for adding files to snapshot manifest working dir. Ready for multithreading.<a name="line.76"></a>
+<span class="sourceLineNo">077</span> */<a name="line.77"></a>
+<span class="sourceLineNo">078</span> public static class RegionSnapshotTask implements Callable<Void> {<a name="line.78"></a>
+<span class="sourceLineNo">079</span> private Region region;<a name="line.79"></a>
+<span class="sourceLineNo">080</span> private boolean skipFlush;<a name="line.80"></a>
+<span class="sourceLineNo">081</span> private ForeignExceptionDispatcher monitor;<a name="line.81"></a>
+<span class="sourceLineNo">082</span> private SnapshotDescription snapshotDesc;<a name="line.82"></a>
+<span class="sourceLineNo">083</span><a name="line.83"></a>
+<span class="sourceLineNo">084</span> public RegionSnapshotTask(Region region, SnapshotDescription snapshotDesc,<a name="line.84"></a>
+<span class="sourceLineNo">085</span> boolean skipFlush, ForeignExceptionDispatcher monitor) {<a name="line.85"></a>
+<span class="sourceLineNo">086</span> this.region = region;<a name="line.86"></a>
+<span class="sourceLineNo">087</span> this.skipFlush = skipFlush;<a name="line.87"></a>
+<span class="sourceLineNo">088</span> this.monitor = monitor;<a name="line.88"></a>
+<span class="sourceLineNo">089</span> this.snapshotDesc = snapshotDesc;<a name="line.89"></a>
+<span class="sourceLineNo">090</span> }<a name="line.90"></a>
+<span class="sourceLineNo">091</span><a name="line.91"></a>
+<span class="sourceLineNo">092</span> @Override<a name="line.92"></a>
+<span class="sourceLineNo">093</span> public Void call() throws Exception {<a name="line.93"></a>
+<span class="sourceLineNo">094</span> // Taking the region read lock prevents the individual region from being closed while a<a name="line.94"></a>
+<span class="sourceLineNo">095</span> // snapshot is in progress. This is helpful but not sufficient for preventing races with<a name="line.95"></a>
+<span class="sourceLineNo">096</span> // snapshots that involve multiple regions and regionservers. It is still possible to have<a name="line.96"></a>
+<span class="sourceLineNo">097</span> // an interleaving such that globally regions are missing, so we still need the verification<a name="line.97"></a>
+<span class="sourceLineNo">098</span> // step.<a name="line.98"></a>
+<span class="sourceLineNo">099</span> LOG.debug("Starting snapshot operation on " + region);<a name="line.99"></a>
+<span class="sourceLineNo">100</span> region.startRegionOperation(Operation.SNAPSHOT);<a name="line.100"></a>
+<span class="sourceLineNo">101</span> try {<a name="line.101"></a>
+<span class="sourceLineNo">102</span> if (skipFlush) {<a name="line.102"></a>
+<span class="sourceLineNo">103</span> /*<a name="line.103"></a>
+<span class="sourceLineNo">104</span> * This is to take an online-snapshot without force a coordinated flush to prevent pause<a name="line.104"></a>
+<span class="sourceLineNo">105</span> * The snapshot type is defined inside the snapshot description. FlushSnapshotSubprocedure<a name="line.105"></a>
+<span class="sourceLineNo">106</span> * should be renamed to distributedSnapshotSubprocedure, and the flush() behavior can be<a name="line.106"></a>
+<span class="sourceLineNo">107</span> * turned on/off based on the flush type.<a name="line.107"></a>
+<span class="sourceLineNo">108</span> * To minimized the code change, class name is not changed.<a name="line.108"></a>
+<span class="sourceLineNo">109</span> */<a name="line.109"></a>
+<span class="sourceLineNo">110</span> LOG.debug("take snapshot without flush memstore first");<a name="line.110"></a>
+<span class="sourceLineNo">111</span> } else {<a name="line.111"></a>
+<span class="sourceLineNo">112</span> LOG.debug("Flush Snapshotting region " + region.toString() + " started...");<a name="line.112"></a>
+<span class="sourceLineNo">113</span> boolean succeeded = false;<a name="line.113"></a>
+<span class="sourceLineNo">114</span> long readPt = region.getReadpoint(IsolationLevel.READ_COMMITTED);<a name="line.114"></a>
+<span class="sourceLineNo">115</span> for (int i = 0; i < MAX_RETRIES; i++) {<a name="line.115"></a>
+<span class="sourceLineNo">116</span> FlushResult res = region.flush(true);<a name="line.116"></a>
+<span class="sourceLineNo">117</span> if (res.getResult() == FlushResult.Result.CANNOT_FLUSH) {<a name="line.117"></a>
+<span class="sourceLineNo">118</span> // CANNOT_FLUSH may mean that a flush is already on-going<a name="line.118"></a>
+<span class="sourceLineNo">119</span> // we need to wait for that flush to complete<a name="line.119"></a>
+<span class="sourceLineNo">120</span> region.waitForFlushes();<a name="line.120"></a>
+<span class="sourceLineNo">121</span> if (region.getMaxFlushedSeqId() >= readPt) {<a name="line.121"></a>
+<span class="sourceLineNo">122</span> // writes at the start of the snapshot have been persisted<a name="line.122"></a>
+<span class="sourceLineNo">123</span> succeeded = true;<a name="line.123"></a>
+<span class="sourceLineNo">124</span> break;<a name="line.124"></a>
+<span class="sourceLineNo">125</span> }<a name="line.125"></a>
+<span class="sourceLineNo">126</span> } else {<a name="line.126"></a>
+<span class="sourceLineNo">127</span> succeeded = true;<a name="line.127"></a>
+<span class="sourceLineNo">128</span> break;<a name="line.128"></a>
+<span class="sourceLineNo">129</span> }<a name="line.129"></a>
+<span class="sourceLineNo">130</span> }<a name="line.130"></a>
+<span class="sourceLineNo">131</span> if (!succeeded) {<a name="line.131"></a>
+<span class="sourceLineNo">132</span> throw new IOException("Unable to complete flush after " + MAX_RETRIES + " attempts");<a name="line.132"></a>
+<span class="sourceLineNo">133</span> }<a name="line.133"></a>
+<span class="sourceLineNo">134</span> }<a name="line.134"></a>
+<span class="sourceLineNo">135</span> ((HRegion)region).addRegionToSnapshot(snapshotDesc, monitor);<a name="line.135"></a>
+<span class="sourceLineNo">136</span> if (skipFlush) {<a name="line.136"></a>
+<span class="sourceLineNo">137</span> LOG.debug("... SkipFlush Snapshotting region " + region.toString() + " completed.");<a name="line.137"></a>
+<span class="sourceLineNo">138</span> } else {<a name="line.138"></a>
+<span class="sourceLineNo">139</span> LOG.debug("... Flush Snapshotting region " + region.toString() + " completed.");<a name="line.139"></a>
+<span class="sourceLineNo">140</span> }<a name="line.140"></a>
+<span class="sourceLineNo">141</span> } finally {<a name="line.141"></a>
+<span class="sourceLineNo">142</span> LOG.debug("Closing snapshot operation on " + region);<a name="line.142"></a>
+<span class="sourceLineNo">143</span> region.closeRegionOperation(Operation.SNAPSHOT);<a name="line.143"></a>
+<span class="sourceLineNo">144</span> }<a name="line.144"></a>
+<span class="sourceLineNo">145</span> return null;<a name="line.145"></a>
+<span class="sourceLineNo">146</span> }<a name="line.146"></a>
+<span class="sourceLineNo">147</span> }<a name="line.147"></a>
+<span class="sourceLineNo">148</span><a name="line.148"></a>
+<span class="sourceLineNo">149</span> private void flushSnapshot() throws ForeignException {<a name="line.149"></a>
+<span class="sourceLineNo">150</span> if (regions.isEmpty()) {<a name="line.150"></a>
+<span class="sourceLineNo">151</span> // No regions on this RS, we are basically done.<a name="line.151"></a>
+<span class="sourceLineNo">152</span> return;<a name="line.152"></a>
<span class="sourceLineNo">153</span> }<a name="line.153"></a>
<span class="sourceLineNo">154</span><a name="line.154"></a>
-<span class="sourceLineNo">155</span> // Add all hfiles already existing in region.<a name="line.155"></a>
-<span class="sourceLineNo">156</span> for (Region region : regions) {<a name="line.156"></a>
-<span class="sourceLineNo">157</span> // submit one task per region for parallelize by region.<a name="line.157"></a>
-<span class="sourceLineNo">158</span> taskManager.submitTask(new RegionSnapshotTask(region));<a name="line.158"></a>
-<span class="sourceLineNo">159</span> monitor.rethrowException();<a name="line.159"></a>
-<span class="sourceLineNo">160</span> }<a name="line.160"></a>
-<span class="sourceLineNo">161</span><a name="line.161"></a>
-<span class="sourceLineNo">162</span> // wait for everything to complete.<a name="line.162"></a>
-<span class="sourceLineNo">163</span> LOG.debug("Flush Snapshot Tasks submitted for " + regions.size() + " regions");<a name="line.163"></a>
-<span class="sourceLineNo">164</span> try {<a name="line.164"></a>
-<span class="sourceLineNo">165</span> taskManager.waitForOutstandingTasks();<a name="line.165"></a>
-<span class="sourceLineNo">166</span> } catch (InterruptedException e) {<a name="line.166"></a>
-<span class="sourceLineNo">167</span> LOG.error("got interrupted exception for " + getMemberName());<a name="line.167"></a>
-<span class="sourceLineNo">168</span> throw new ForeignException(getMemberName(), e);<a name="line.168"></a>
+<span class="sourceLineNo">155</span> monitor.rethrowException();<a name="line.155"></a>
+<span class="sourceLineNo">156</span><a name="line.156"></a>
+<span class="sourceLineNo">157</span> // assert that the taskManager is empty.<a name="line.157"></a>
+<span class="sourceLineNo">158</span> if (taskManager.hasTasks()) {<a name="line.158"></a>
+<span class="sourceLineNo">159</span> throw new IllegalStateException("Attempting to take snapshot "<a name="line.159"></a>
+<span class="sourceLineNo">160</span> + ClientSnapshotDescriptionUtils.toString(snapshot)<a name="line.160"></a>
+<span class="sourceLineNo">161</span> + " but we currently have outstanding tasks");<a name="line.161"></a>
+<span class="sourceLineNo">162</span> }<a name="line.162"></a>
+<span class="sourceLineNo">163</span><a name="line.163"></a>
+<span class="sourceLineNo">164</span> // Add all hfiles already existing in region.<a name="line.164"></a>
+<span class="sourceLineNo">165</span> for (Region region : regions) {<a name="line.165"></a>
+<span class="sourceLineNo">166</span> // submit one task per region for parallelize by region.<a name="line.166"></a>
+<span class="sourceLineNo">167</span> taskManager.submitTask(new RegionSnapshotTask(region, snapshot, snapshotSkipFlush, monitor));<a name="line.167"></a>
+<span class="sourceLineNo">168</span> monitor.rethrowException();<a name="line.168"></a>
<span class="sourceLineNo">169</span> }<a name="line.169"></a>
-<span class="sourceLineNo">170</span> }<a name="line.170"></a>
-<span class="sourceLineNo">171</span><a name="line.171"></a>
-<span class="sourceLineNo">172</span> /**<a name="line.172"></a>
-<span class="sourceLineNo">173</span> * do nothing, core of snapshot is executed in {@link #insideBarrier} step.<a name="line.173"></a>
-<span class="sourceLineNo">174</span> */<a name="line.174"></a>
-<span class="sourceLineNo">175</span> @Override<a name="line.175"></a>
-<span class="sourceLineNo">176</span> public void acquireBarrier() throws ForeignException {<a name="line.176"></a>
-<span class="sourceLineNo">177</span> // NO OP<a name="line.177"></a>
-<span class="sourceLineNo">178</span> }<a name="line.178"></a>
-<span class="sourceLineNo">179</span><a name="line.179"></a>
-<span class="sourceLineNo">180</span> /**<a name="line.180"></a>
-<span class="sourceLineNo">181</span> * do a flush snapshot of every region on this rs from the target table.<a name="line.181"></a>
-<span class="sourceLineNo">182</span> */<a name="line.182"></a>
-<span class="sourceLineNo">183</span> @Override<a name="line.183"></a>
-<span class="sourceLineNo">184</span> public byte[] insideBarrier() throws ForeignException {<a name="line.184"></a>
-<span class="sourceLineNo">185</span> flushSnapshot();<a name="line.185"></a>
-<span class="sourceLineNo">186</span> return new byte[0];<a name="line.186"></a>
+<span class="sourceLineNo">170</span><a name="line.170"></a>
+<span class="sourceLineNo">171</span> // wait for everything to complete.<a name="line.171"></a>
+<span class="sourceLineNo">172</span> LOG.debug("Flush Snapshot Tasks submitted for " + regions.size() + " regions");<a name="line.172"></a>
+<span class="sourceLineNo">173</span> try {<a name="line.173"></a>
+<span class="sourceLineNo">174</span> taskManager.waitForOutstandingTasks();<a name="line.174"></a>
+<span class="sourceLineNo">175</span> } catch (InterruptedException e) {<a name="line.175"></a>
+<span class="sourceLineNo">176</span> LOG.error("got interrupted exception for " + getMemberName());<a name="line.176"></a>
+<span class="sourceLineNo">177</span> throw new ForeignException(getMemberName(), e);<a name="line.177"></a>
+<span class="sourceLineNo">178</span> }<a name="line.178"></a>
+<span class="sourceLineNo">179</span> }<a name="line.179"></a>
+<span class="sourceLineNo">180</span><a name="line.180"></a>
+<span class="sourceLineNo">181</span> /**<a name="line.181"></a>
+<span class="sourceLineNo">182</span> * do nothing, core of snapshot is executed in {@link #insideBarrier} step.<a name="line.182"></a>
+<span class="sourceLineNo">183</span> */<a name="line.183"></a>
+<span class="sourceLineNo">184</span> @Override<a name="line.184"></a>
+<span class="sourceLineNo">185</span> public void acquireBarrier() throws ForeignException {<a name="line.185"></a>
+<span class="sourceLineNo">186</span> // NO OP<a name="line.186"></a>
<span class="sourceLineNo">187</span> }<a name="line.187"></a>
<span class="sourceLineNo">188</span><a name="line.188"></a>
<span class="sourceLineNo">189</span> /**<a name="line.189"></a>
-<span class="sourceLineNo">190</span> * Cancel threads if they haven't finished.<a name="line.190"></a>
+<span class="sourceLineNo">190</span> * do a flush snapshot of every region on this rs from the target table.<a name="line.190"></a>
<span class="sourceLineNo">191</span> */<a name="line.191"></a>
<span class="sourceLineNo">192</span> @Override<a name="line.192"></a>
-<span class="sourceLineNo">193</span> public void cleanup(Exception e) {<a name="line.193"></a>
-<span class="sourceLineNo">194</span> LOG.info("Aborting all online FLUSH snapshot subprocedure task threads for '"<a name="line.194"></a>
-<span class="sourceLineNo">195</span> + snapshot.getName() + "' due to error", e);<a name="line.195"></a>
-<span class="sourceLineNo">196</span> try {<a name="line.196"></a>
-<span class="sourceLineNo">197</span> taskManager.cancelTasks();<a name="line.197"></a>
-<span class="sourceLineNo">198</span> } catch (InterruptedException e1) {<a name="line.198"></a>
-<span class="sourceLineNo">199</span> Thread.currentThread().interrupt();<a name="line.199"></a>
-<span class="sourceLineNo">200</span> }<a name="line.200"></a>
-<span class="sourceLineNo">201</span> }<a name="line.201"></a>
-<span class="sourceLineNo">202</span><a name="line.202"></a>
-<span class="sourceLineNo">203</span> /**<a name="line.203"></a>
-<span class="sourceLineNo">204</span> * Hooray!<a name="line.204"></a>
-<span class="sourceLineNo">205</span> */<a name="line.205"></a>
-<span class="sourceLineNo">206</span> public void releaseBarrier() {<a name="line.206"></a>
-<span class="sourceLineNo">207</span> // NO OP<a name="line.207"></a>
-<span class="sourceLineNo">208</span> }<a name="line.208"></a>
-<span class="sourceLineNo">209</span><a name="line.209"></a>
-<span class="sourceLineNo">210</span>}<a name="line.210"></a>
+<span class="sourceLineNo">193</span> public byte[] insideBarrier() throws ForeignException {<a name="line.193"></a>
+<span class="sourceLineNo">194</span> flushSnapshot();<a name="line.194"></a>
+<span class="sourceLineNo">195</span> return new byte[0];<a name="line.195"></a>
+<span class="sourceLineNo">196</span> }<a name="line.196"></a>
+<span class="sourceLineNo">197</span><a name="line.197"></a>
+<span class="sourceLineNo">198</span> /**<a name="line.198"></a>
+<span class="sourceLineNo">199</span> * Cancel threads if they haven't finished.<a name="line.199"></a>
+<span class="sourceLineNo">200</span> */<a name="line.200"></a>
+<span class="sourceLineNo">201</span> @Override<a name="line.201"></a>
+<span class="sourceLineNo">202</span> public void cleanup(Exception e) {<a name="line.202"></a>
+<span class="sourceLineNo">203</span> LOG.info("Aborting all online FLUSH snapshot subprocedure task threads for '"<a name="line.203"></a>
+<span class="sourceLineNo">204</span> + snapshot.getName() + "' due to error", e);<a name="line.204"></a>
+<span class="sourceLineNo">205</span> try {<a name="line.205"></a>
+<span class="sourceLineNo">206</span> taskManager.cancelTasks();<a name="line.206"></a>
+<span class="sourceLineNo">207</span> } catch (InterruptedException e1) {<a name="line.207"></a>
+<span class="sourceLineNo">208</span> Thread.currentThread().interrupt();<a name="line.208"></a>
+<span class="sourceLineNo">209</span> }<a name="line.209"></a>
+<span class="sourceLineNo">210</span> }<a name="line.210"></a>
+<span class="sourceLineNo">211</span><a name="line.211"></a>
+<span class="sourceLineNo">212</span> /**<a name="line.212"></a>
+<span class="sourceLineNo">213</span> * Hooray!<a name="line.213"></a>
+<span class="sourceLineNo">214</span> */<a name="line.214"></a>
+<span class="sourceLineNo">215</span> public void releaseBarrier() {<a name="line.215"></a>
+<span class="sourceLineNo">216</span> // NO OP<a name="line.216"></a>
+<span class="sourceLineNo">217</span> }<a name="line.217"></a>
+<span class="sourceLineNo">218</span><a name="line.218"></a>
+<span class="sourceLineNo">219</span>}<a name="line.219"></a>
http://git-wip-us.apache.org/repos/asf/hbase-site/blob/99c53df1/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/snapshot/FlushSnapshotSubprocedure.html
----------------------------------------------------------------------
diff --git a/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/snapshot/FlushSnapshotSubprocedure.html b/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/snapshot/FlushSnapshotSubprocedure.html
index c73100f..b3c1730 100644
--- a/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/snapshot/FlushSnapshotSubprocedure.html
+++ b/devapidocs/src-html/org/apache/hadoop/hbase/regionserver/snapshot/FlushSnapshotSubprocedure.html
@@ -41,181 +41,190 @@
<span class="sourceLineNo">033</span>import org.apache.hadoop.hbase.regionserver.HRegion;<a name="line.33"></a>
<span class="sourceLineNo">034</span>import org.apache.hadoop.hbase.regionserver.Region;<a name="line.34"></a>
<span class="sourceLineNo">035</span>import org.apache.hadoop.hbase.regionserver.Region.FlushResult;<a name="line.35"></a>
-<span class="sourceLineNo">036</span>import org.apache.hadoop.hbase.regionserver.snapshot.RegionServerSnapshotManager.SnapshotSubprocedurePool;<a name="line.36"></a>
-<span class="sourceLineNo">037</span>import org.apache.hadoop.hbase.shaded.protobuf.generated.SnapshotProtos.SnapshotDescription;<a name="line.37"></a>
-<span class="sourceLineNo">038</span>import org.apache.hadoop.hbase.snapshot.ClientSnapshotDescriptionUtils;<a name="line.38"></a>
-<span class="sourceLineNo">039</span><a name="line.39"></a>
-<span class="sourceLineNo">040</span>/**<a name="line.40"></a>
-<span class="sourceLineNo">041</span> * This online snapshot implementation uses the distributed procedure framework to force a<a name="line.41"></a>
-<span class="sourceLineNo">042</span> * store flush and then records the hfiles. Its enter stage does nothing. Its leave stage then<a name="line.42"></a>
-<span class="sourceLineNo">043</span> * flushes the memstore, builds the region server's snapshot manifest from its hfiles list, and<a name="line.43"></a>
-<span class="sourceLineNo">044</span> * copies .regioninfos into the snapshot working directory. At the master side, there is an atomic<a name="line.44"></a>
-<span class="sourceLineNo">045</span> * rename of the working dir into the proper snapshot directory.<a name="line.45"></a>
-<span class="sourceLineNo">046</span> */<a name="line.46"></a>
-<span class="sourceLineNo">047</span>@InterfaceAudience.Private<a name="line.47"></a>
-<span class="sourceLineNo">048</span>@InterfaceStability.Unstable<a name="line.48"></a>
-<span class="sourceLineNo">049</span>public class FlushSnapshotSubprocedure extends Subprocedure {<a name="line.49"></a>
-<span class="sourceLineNo">050</span> private static final Log LOG = LogFactory.getLog(FlushSnapshotSubprocedure.class);<a name="line.50"></a>
-<span class="sourceLineNo">051</span><a name="line.51"></a>
-<span class="sourceLineNo">052</span> private final List<Region> regions;<a name="line.52"></a>
-<span class="sourceLineNo">053</span> private final SnapshotDescription snapshot;<a name="line.53"></a>
-<span class="sourceLineNo">054</span> private final SnapshotSubprocedurePool taskManager;<a name="line.54"></a>
-<span class="sourceLineNo">055</span> private boolean snapshotSkipFlush = false;<a name="line.55"></a>
-<span class="sourceLineNo">056</span><a name="line.56"></a>
-<span class="sourceLineNo">057</span> // the maximum number of attempts we flush<a name="line.57"></a>
-<span class="sourceLineNo">058</span> final static int MAX_RETRIES = 3;<a name="line.58"></a>
-<span class="sourceLineNo">059</span><a name="line.59"></a>
-<span class="sourceLineNo">060</span> public FlushSnapshotSubprocedure(ProcedureMember member,<a name="line.60"></a>
-<span class="sourceLineNo">061</span> ForeignExceptionDispatcher errorListener, long wakeFrequency, long timeout,<a name="line.61"></a>
-<span class="sourceLineNo">062</span> List<Region> regions, SnapshotDescription snapshot,<a name="line.62"></a>
-<span class="sourceLineNo">063</span> SnapshotSubprocedurePool taskManager) {<a name="line.63"></a>
-<span class="sourceLineNo">064</span> super(member, snapshot.getName(), errorListener, wakeFrequency, timeout);<a name="line.64"></a>
-<span class="sourceLineNo">065</span> this.snapshot = snapshot;<a name="line.65"></a>
-<span class="sourceLineNo">066</span><a name="line.66"></a>
-<span class="sourceLineNo">067</span> if (this.snapshot.getType() == SnapshotDescription.Type.SKIPFLUSH) {<a name="line.67"></a>
-<span class="sourceLineNo">068</span> snapshotSkipFlush = true;<a name="line.68"></a>
-<span class="sourceLineNo">069</span> }<a name="line.69"></a>
-<span class="sourceLineNo">070</span> this.regions = regions;<a name="line.70"></a>
-<span class="sourceLineNo">071</span> this.taskManager = taskManager;<a name="line.71"></a>
-<span class="sourceLineNo">072</span> }<a name="line.72"></a>
-<span class="sourceLineNo">073</span><a name="line.73"></a>
-<span class="sourceLineNo">074</span> /**<a name="line.74"></a>
-<span class="sourceLineNo">075</span> * Callable for adding files to snapshot manifest working dir. Ready for multithreading.<a name="line.75"></a>
-<span class="sourceLineNo">076</span> */<a name="line.76"></a>
-<span class="sourceLineNo">077</span> private class RegionSnapshotTask implements Callable<Void> {<a name="line.77"></a>
-<span class="sourceLineNo">078</span> Region region;<a name="line.78"></a>
-<span class="sourceLineNo">079</span> RegionSnapshotTask(Region region) {<a name="line.79"></a>
-<span class="sourceLineNo">080</span> this.region = region;<a name="line.80"></a>
-<span class="sourceLineNo">081</span> }<a name="line.81"></a>
-<span class="sourceLineNo">082</span><a name="line.82"></a>
-<span class="sourceLineNo">083</span> @Override<a name="line.83"></a>
-<span class="sourceLineNo">084</span> public Void call() throws Exception {<a name="line.84"></a>
-<span class="sourceLineNo">085</span> // Taking the region read lock prevents the individual region from being closed while a<a name="line.85"></a>
-<span class="sourceLineNo">086</span> // snapshot is in progress. This is helpful but not sufficient for preventing races with<a name="line.86"></a>
-<span class="sourceLineNo">087</span> // snapshots that involve multiple regions and regionservers. It is still possible to have<a name="line.87"></a>
-<span class="sourceLineNo">088</span> // an interleaving such that globally regions are missing, so we still need the verification<a name="line.88"></a>
-<span class="sourceLineNo">089</span> // step.<a name="line.89"></a>
-<span class="sourceLineNo">090</span> LOG.debug("Starting region operation on " + region);<a name="line.90"></a>
-<span class="sourceLineNo">091</span> region.startRegionOperation();<a name="line.91"></a>
-<span class="sourceLineNo">092</span> try {<a name="line.92"></a>
-<span class="sourceLineNo">093</span> if (snapshotSkipFlush) {<a name="line.93"></a>
-<span class="sourceLineNo">094</span> /*<a name="line.94"></a>
-<span class="sourceLineNo">095</span> * This is to take an online-snapshot without force a coordinated flush to prevent pause<a name="line.95"></a>
-<span class="sourceLineNo">096</span> * The snapshot type is defined inside the snapshot description. FlushSnapshotSubprocedure<a name="line.96"></a>
-<span class="sourceLineNo">097</span> * should be renamed to distributedSnapshotSubprocedure, and the flush() behavior can be<a name="line.97"></a>
-<span class="sourceLineNo">098</span> * turned on/off based on the flush type.<a name="line.98"></a>
-<span class="sourceLineNo">099</span> * To minimized the code change, class name is not changed.<a name="line.99"></a>
-<span class="sourceLineNo">100</span> */<a name="line.100"></a>
-<span class="sourceLineNo">101</span> LOG.debug("take snapshot without flush memstore first");<a name="line.101"></a>
-<span class="sourceLineNo">102</span> } else {<a name="line.102"></a>
-<span class="sourceLineNo">103</span> LOG.debug("Flush Snapshotting region " + region.toString() + " started...");<a name="line.103"></a>
-<span class="sourceLineNo">104</span> boolean succeeded = false;<a name="line.104"></a>
-<span class="sourceLineNo">105</span> long readPt = region.getReadpoint(IsolationLevel.READ_COMMITTED);<a name="line.105"></a>
-<span class="sourceLineNo">106</span> for (int i = 0; i < MAX_RETRIES; i++) {<a name="line.106"></a>
-<span class="sourceLineNo">107</span> FlushResult res = region.flush(true);<a name="line.107"></a>
-<span class="sourceLineNo">108</span> if (res.getResult() == FlushResult.Result.CANNOT_FLUSH) {<a name="line.108"></a>
-<span class="sourceLineNo">109</span> // CANNOT_FLUSH may mean that a flush is already on-going<a name="line.109"></a>
-<span class="sourceLineNo">110</span> // we need to wait for that flush to complete<a name="line.110"></a>
-<span class="sourceLineNo">111</span> region.waitForFlushes();<a name="line.111"></a>
-<span class="sourceLineNo">112</span> if (region.getMaxFlushedSeqId() >= readPt) {<a name="line.112"></a>
-<span class="sourceLineNo">113</span> // writes at the start of the snapshot have been persisted<a name="line.113"></a>
-<span class="sourceLineNo">114</span> succeeded = true;<a name="line.114"></a>
-<span class="sourceLineNo">115</span> break;<a name="line.115"></a>
-<span class="sourceLineNo">116</span> }<a name="line.116"></a>
-<span class="sourceLineNo">117</span> } else {<a name="line.117"></a>
-<span class="sourceLineNo">118</span> succeeded = true;<a name="line.118"></a>
-<span class="sourceLineNo">119</span> break;<a name="line.119"></a>
-<span class="sourceLineNo">120</span> }<a name="line.120"></a>
-<span class="sourceLineNo">121</span> }<a name="line.121"></a>
-<span class="sourceLineNo">122</span> if (!succeeded) {<a name="line.122"></a>
-<span class="sourceLineNo">123</span> throw new IOException("Unable to complete flush after " + MAX_RETRIES + " attempts");<a name="line.123"></a>
-<span class="sourceLineNo">124</span> }<a name="line.124"></a>
-<span class="sourceLineNo">125</span> }<a name="line.125"></a>
-<span class="sourceLineNo">126</span> ((HRegion)region).addRegionToSnapshot(snapshot, monitor);<a name="line.126"></a>
-<span class="sourceLineNo">127</span> if (snapshotSkipFlush) {<a name="line.127"></a>
-<span class="sourceLineNo">128</span> LOG.debug("... SkipFlush Snapshotting region " + region.toString() + " completed.");<a name="line.128"></a>
-<span class="sourceLineNo">129</span> } else {<a name="line.129"></a>
-<span class="sourceLineNo">130</span> LOG.debug("... Flush Snapshotting region " + region.toString() + " completed.");<a name="line.130"></a>
-<span class="sourceLineNo">131</span> }<a name="line.131"></a>
-<span class="sourceLineNo">132</span> } finally {<a name="line.132"></a>
-<span class="sourceLineNo">133</span> LOG.debug("Closing region operation on " + region);<a name="line.133"></a>
-<span class="sourceLineNo">134</span> region.closeRegionOperation();<a name="line.134"></a>
-<span class="sourceLineNo">135</span> }<a name="line.135"></a>
-<span class="sourceLineNo">136</span> return null;<a name="line.136"></a>
-<span class="sourceLineNo">137</span> }<a name="line.137"></a>
-<span class="sourceLineNo">138</span> }<a name="line.138"></a>
-<span class="sourceLineNo">139</span><a name="line.139"></a>
-<span class="sourceLineNo">140</span> private void flushSnapshot() throws ForeignException {<a name="line.140"></a>
-<span class="sourceLineNo">141</span> if (regions.isEmpty()) {<a name="line.141"></a>
-<span class="sourceLineNo">142</span> // No regions on this RS, we are basically done.<a name="line.142"></a>
-<span class="sourceLineNo">143</span> return;<a name="line.143"></a>
-<span class="sourceLineNo">144</span> }<a name="line.144"></a>
-<span class="sourceLineNo">145</span><a name="line.145"></a>
-<span class="sourceLineNo">146</span> monitor.rethrowException();<a name="line.146"></a>
-<span class="sourceLineNo">147</span><a name="line.147"></a>
-<span class="sourceLineNo">148</span> // assert that the taskManager is empty.<a name="line.148"></a>
-<span class="sourceLineNo">149</span> if (taskManager.hasTasks()) {<a name="line.149"></a>
-<span class="sourceLineNo">150</span> throw new IllegalStateException("Attempting to take snapshot "<a name="line.150"></a>
-<span class="sourceLineNo">151</span> + ClientSnapshotDescriptionUtils.toString(snapshot)<a name="line.151"></a>
-<span class="sourceLineNo">152</span> + " but we currently have outstanding tasks");<a name="line.152"></a>
+<span class="sourceLineNo">036</span>import org.apache.hadoop.hbase.regionserver.Region.Operation;<a name="line.36"></a>
+<span class="sourceLineNo">037</span>import org.apache.hadoop.hbase.regionserver.snapshot.RegionServerSnapshotManager.SnapshotSubprocedurePool;<a name="line.37"></a>
+<span class="sourceLineNo">038</span>import org.apache.hadoop.hbase.shaded.protobuf.generated.SnapshotProtos.SnapshotDescription;<a name="line.38"></a>
+<span class="sourceLineNo">039</span>import org.apache.hadoop.hbase.snapshot.ClientSnapshotDescriptionUtils;<a name="line.39"></a>
+<span class="sourceLineNo">040</span><a name="line.40"></a>
+<span class="sourceLineNo">041</span>/**<a name="line.41"></a>
+<span class="sourceLineNo">042</span> * This online snapshot implementation uses the distributed procedure framework to force a<a name="line.42"></a>
+<span class="sourceLineNo">043</span> * store flush and then records the hfiles. Its enter stage does nothing. Its leave stage then<a name="line.43"></a>
+<span class="sourceLineNo">044</span> * flushes the memstore, builds the region server's snapshot manifest from its hfiles list, and<a name="line.44"></a>
+<span class="sourceLineNo">045</span> * copies .regioninfos into the snapshot working directory. At the master side, there is an atomic<a name="line.45"></a>
+<span class="sourceLineNo">046</span> * rename of the working dir into the proper snapshot directory.<a name="line.46"></a>
+<span class="sourceLineNo">047</span> */<a name="line.47"></a>
+<span class="sourceLineNo">048</span>@InterfaceAudience.Private<a name="line.48"></a>
+<span class="sourceLineNo">049</span>@InterfaceStability.Unstable<a name="line.49"></a>
+<span class="sourceLineNo">050</span>public class FlushSnapshotSubprocedure extends Subprocedure {<a name="line.50"></a>
+<span class="sourceLineNo">051</span> private static final Log LOG = LogFactory.getLog(FlushSnapshotSubprocedure.class);<a name="line.51"></a>
+<span class="sourceLineNo">052</span><a name="line.52"></a>
+<span class="sourceLineNo">053</span> private final List<Region> regions;<a name="line.53"></a>
+<span class="sourceLineNo">054</span> private final SnapshotDescription snapshot;<a name="line.54"></a>
+<span class="sourceLineNo">055</span> private final SnapshotSubprocedurePool taskManager;<a name="line.55"></a>
+<span class="sourceLineNo">056</span> private boolean snapshotSkipFlush = false;<a name="line.56"></a>
+<span class="sourceLineNo">057</span><a name="line.57"></a>
+<span class="sourceLineNo">058</span> // the maximum number of attempts we flush<a name="line.58"></a>
+<span class="sourceLineNo">059</span> final static int MAX_RETRIES = 3;<a name="line.59"></a>
+<span class="sourceLineNo">060</span><a name="line.60"></a>
+<span class="sourceLineNo">061</span> public FlushSnapshotSubprocedure(ProcedureMember member,<a name="line.61"></a>
+<span class="sourceLineNo">062</span> ForeignExceptionDispatcher errorListener, long wakeFrequency, long timeout,<a name="line.62"></a>
+<span class="sourceLineNo">063</span> List<Region> regions, SnapshotDescription snapshot,<a name="line.63"></a>
+<span class="sourceLineNo">064</span> SnapshotSubprocedurePool taskManager) {<a name="line.64"></a>
+<span class="sourceLineNo">065</span> super(member, snapshot.getName(), errorListener, wakeFrequency, timeout);<a name="line.65"></a>
+<span class="sourceLineNo">066</span> this.snapshot = snapshot;<a name="line.66"></a>
+<span class="sourceLineNo">067</span><a name="line.67"></a>
+<span class="sourceLineNo">068</span> if (this.snapshot.getType() == SnapshotDescription.Type.SKIPFLUSH) {<a name="line.68"></a>
+<span class="sourceLineNo">069</span> snapshotSkipFlush = true;<a name="line.69"></a>
+<span class="sourceLineNo">070</span> }<a name="line.70"></a>
+<span class="sourceLineNo">071</span> this.regions = regions;<a name="line.71"></a>
+<span class="sourceLineNo">072</span> this.taskManager = taskManager;<a name="line.72"></a>
+<span class="sourceLineNo">073</span> }<a name="line.73"></a>
+<span class="sourceLineNo">074</span><a name="line.74"></a>
+<span class="sourceLineNo">075</span> /**<a name="line.75"></a>
+<span class="sourceLineNo">076</span> * Callable for adding files to snapshot manifest working dir. Ready for multithreading.<a name="line.76"></a>
+<span class="sourceLineNo">077</span> */<a name="line.77"></a>
+<span class="sourceLineNo">078</span> public static class RegionSnapshotTask implements Callable<Void> {<a name="line.78"></a>
+<span class="sourceLineNo">079</span> private Region region;<a name="line.79"></a>
+<span class="sourceLineNo">080</span> private boolean skipFlush;<a name="line.80"></a>
+<span class="sourceLineNo">081</span> private ForeignExceptionDispatcher monitor;<a name="line.81"></a>
+<span class="sourceLineNo">082</span> private SnapshotDescription snapshotDesc;<a name="line.82"></a>
+<span class="sourceLineNo">083</span><a name="line.83"></a>
+<span class="sourceLineNo">084</span> public RegionSnapshotTask(Region region, SnapshotDescription snapshotDesc,<a name="line.84"></a>
+<span class="sourceLineNo">085</span> boolean skipFlush, ForeignExceptionDispatcher monitor) {<a name="line.85"></a>
+<span class="sourceLineNo">086</span> this.region = region;<a name="line.86"></a>
+<span class="sourceLineNo">087</span> this.skipFlush = skipFlush;<a name="line.87"></a>
+<span class="sourceLineNo">088</span> this.monitor = monitor;<a name="line.88"></a>
+<span class="sourceLineNo">089</span> this.snapshotDesc = snapshotDesc;<a name="line.89"></a>
+<span class="sourceLineNo">090</span> }<a name="line.90"></a>
+<span class="sourceLineNo">091</span><a name="line.91"></a>
+<span class="sourceLineNo">092</span> @Override<a name="line.92"></a>
+<span class="sourceLineNo">093</span> public Void call() throws Exception {<a name="line.93"></a>
+<span class="sourceLineNo">094</span> // Taking the region read lock prevents the individual region from being closed while a<a name="line.94"></a>
+<span class="sourceLineNo">095</span> // snapshot is in progress. This is helpful but not sufficient for preventing races with<a name="line.95"></a>
+<span class="sourceLineNo">096</span> // snapshots that involve multiple regions and regionservers. It is still possible to have<a name="line.96"></a>
+<span class="sourceLineNo">097</span> // an interleaving such that globally regions are missing, so we still need the verification<a name="line.97"></a>
+<span class="sourceLineNo">098</span> // step.<a name="line.98"></a>
+<span class="sourceLineNo">099</span> LOG.debug("Starting snapshot operation on " + region);<a name="line.99"></a>
+<span class="sourceLineNo">100</span> region.startRegionOperation(Operation.SNAPSHOT);<a name="line.100"></a>
+<span class="sourceLineNo">101</span> try {<a name="line.101"></a>
+<span class="sourceLineNo">102</span> if (skipFlush) {<a name="line.102"></a>
+<span class="sourceLineNo">103</span> /*<a name="line.103"></a>
+<span class="sourceLineNo">104</span> * This is to take an online-snapshot without force a coordinated flush to prevent pause<a name="line.104"></a>
+<span class="sourceLineNo">105</span> * The snapshot type is defined inside the snapshot description. FlushSnapshotSubprocedure<a name="line.105"></a>
+<span class="sourceLineNo">106</span> * should be renamed to distributedSnapshotSubprocedure, and the flush() behavior can be<a name="line.106"></a>
+<span class="sourceLineNo">107</span> * turned on/off based on the flush type.<a name="line.107"></a>
+<span class="sourceLineNo">108</span> * To minimized the code change, class name is not changed.<a name="line.108"></a>
+<span class="sourceLineNo">109</span> */<a name="line.109"></a>
+<span class="sourceLineNo">110</span> LOG.debug("take snapshot without flush memstore first");<a name="line.110"></a>
+<span class="sourceLineNo">111</span> } else {<a name="line.111"></a>
+<span class="sourceLineNo">112</span> LOG.debug("Flush Snapshotting region " + region.toString() + " started...");<a name="line.112"></a>
+<span class="sourceLineNo">113</span> boolean succeeded = false;<a name="line.113"></a>
+<span class="sourceLineNo">114</span> long readPt = region.getReadpoint(IsolationLevel.READ_COMMITTED);<a name="line.114"></a>
+<span class="sourceLineNo">115</span> for (int i = 0; i < MAX_RETRIES; i++) {<a name="line.115"></a>
+<span class="sourceLineNo">116</span> FlushResult res = region.flush(true);<a name="line.116"></a>
+<span class="sourceLineNo">117</span> if (res.getResult() == FlushResult.Result.CANNOT_FLUSH) {<a name="line.117"></a>
+<span class="sourceLineNo">118</span> // CANNOT_FLUSH may mean that a flush is already on-going<a name="line.118"></a>
+<span class="sourceLineNo">119</span> // we need to wait for that flush to complete<a name="line.119"></a>
+<span class="sourceLineNo">120</span> region.waitForFlushes();<a name="line.120"></a>
+<span class="sourceLineNo">121</span> if (region.getMaxFlushedSeqId() >= readPt) {<a name="line.121"></a>
+<span class="sourceLineNo">122</span> // writes at the start of the snapshot have been persisted<a name="line.122"></a>
+<span class="sourceLineNo">123</span> succeeded = true;<a name="line.123"></a>
+<span class="sourceLineNo">124</span> break;<a name="line.124"></a>
+<span class="sourceLineNo">125</span> }<a name="line.125"></a>
+<span class="sourceLineNo">126</span> } else {<a name="line.126"></a>
+<span class="sourceLineNo">127</span> succeeded = true;<a name="line.127"></a>
+<span class="sourceLineNo">128</span> break;<a name="line.128"></a>
+<span class="sourceLineNo">129</span> }<a name="line.129"></a>
+<span class="sourceLineNo">130</span> }<a name="line.130"></a>
+<span class="sourceLineNo">131</span> if (!succeeded) {<a name="line.131"></a>
+<span class="sourceLineNo">132</span> throw new IOException("Unable to complete flush after " + MAX_RETRIES + " attempts");<a name="line.132"></a>
+<span class="sourceLineNo">133</span> }<a name="line.133"></a>
+<span class="sourceLineNo">134</span> }<a name="line.134"></a>
+<span class="sourceLineNo">135</span> ((HRegion)region).addRegionToSnapshot(snapshotDesc, monitor);<a name="line.135"></a>
+<span class="sourceLineNo">136</span> if (skipFlush) {<a name="line.136"></a>
+<span class="sourceLineNo">137</span> LOG.debug("... SkipFlush Snapshotting region " + region.toString() + " completed.");<a name="line.137"></a>
+<span class="sourceLineNo">138</span> } else {<a name="line.138"></a>
+<span class="sourceLineNo">139</span> LOG.debug("... Flush Snapshotting region " + region.toString() + " completed.");<a name="line.139"></a>
+<span class="sourceLineNo">140</span> }<a name="line.140"></a>
+<span class="sourceLineNo">141</span> } finally {<a name="line.141"></a>
+<span class="sourceLineNo">142</span> LOG.debug("Closing snapshot operation on " + region);<a name="line.142"></a>
+<span class="sourceLineNo">143</span> region.closeRegionOperation(Operation.SNAPSHOT);<a name="line.143"></a>
+<span class="sourceLineNo">144</span> }<a name="line.144"></a>
+<span class="sourceLineNo">145</span> return null;<a name="line.145"></a>
+<span class="sourceLineNo">146</span> }<a name="line.146"></a>
+<span class="sourceLineNo">147</span> }<a name="line.147"></a>
+<span class="sourceLineNo">148</span><a name="line.148"></a>
+<span class="sourceLineNo">149</span> private void flushSnapshot() throws ForeignException {<a name="line.149"></a>
+<span class="sourceLineNo">150</span> if (regions.isEmpty()) {<a name="line.150"></a>
+<span class="sourceLineNo">151</span> // No regions on this RS, we are basically done.<a name="line.151"></a>
+<span class="sourceLineNo">152</span> return;<a name="line.152"></a>
<span class="sourceLineNo">153</span> }<a name="line.153"></a>
<span class="sourceLineNo">154</span><a name="line.154"></a>
-<span class="sourceLineNo">155</span> // Add all hfiles already existing in region.<a name="line.155"></a>
-<span class="sourceLineNo">156</span> for (Region region : regions) {<a name="line.156"></a>
-<span class="sourceLineNo">157</span> // submit one task per region for parallelize by region.<a name="line.157"></a>
-<span class="sourceLineNo">158</span> taskManager.submitTask(new RegionSnapshotTask(region));<a name="line.158"></a>
-<span class="sourceLineNo">159</span> monitor.rethrowException();<a name="line.159"></a>
-<span class="sourceLineNo">160</span> }<a name="line.160"></a>
-<span class="sourceLineNo">161</span><a name="line.161"></a>
-<span class="sourceLineNo">162</span> // wait for everything to complete.<a name="line.162"></a>
-<span class="sourceLineNo">163</span> LOG.debug("Flush Snapshot Tasks submitted for " + regions.size() + " regions");<a name="line.163"></a>
-<span class="sourceLineNo">164</span> try {<a name="line.164"></a>
-<span class="sourceLineNo">165</span> taskManager.waitForOutstandingTasks();<a name="line.165"></a>
-<span class="sourceLineNo">166</span> } catch (InterruptedException e) {<a name="line.166"></a>
-<span class="sourceLineNo">167</span> LOG.error("got interrupted exception for " + getMemberName());<a name="line.167"></a>
-<span class="sourceLineNo">168</span> throw new ForeignException(getMemberName(), e);<a name="line.168"></a>
+<span class="sourceLineNo">155</span> monitor.rethrowException();<a name="line.155"></a>
+<span class="sourceLineNo">156</span><a name="line.156"></a>
+<span class="sourceLineNo">157</span> // assert that the taskManager is empty.<a name="line.157"></a>
+<span class="sourceLineNo">158</span> if (taskManager.hasTasks()) {<a name="line.158"></a>
+<span class="sourceLineNo">159</span> throw new IllegalStateException("Attempting to take snapshot "<a name="line.159"></a>
+<span class="sourceLineNo">160</span> + ClientSnapshotDescriptionUtils.toString(snapshot)<a name="line.160"></a>
+<span class="sourceLineNo">161</span> + " but we currently have outstanding tasks");<a name="line.161"></a>
+<span class="sourceLineNo">162</span> }<a name="line.162"></a>
+<span class="sourceLineNo">163</span><a name="line.163"></a>
+<span class="sourceLineNo">164</span> // Add all hfiles already existing in region.<a name="line.164"></a>
+<span class="sourceLineNo">165</span> for (Region region : regions) {<a name="line.165"></a>
+<span class="sourceLineNo">166</span> // submit one task per region for parallelize by region.<a name="line.166"></a>
+<span class="sourceLineNo">167</span> taskManager.submitTask(new RegionSnapshotTask(region, snapshot, snapshotSkipFlush, monitor));<a name="line.167"></a>
+<span class="sourceLineNo">168</span> monitor.rethrowException();<a name="line.168"></a>
<span class="sourceLineNo">169</span> }<a name="line.169"></a>
-<span class="sourceLineNo">170</span> }<a name="line.170"></a>
-<span class="sourceLineNo">171</span><a name="line.171"></a>
-<span class="sourceLineNo">172</span> /**<a name="line.172"></a>
-<span class="sourceLineNo">173</span> * do nothing, core of snapshot is executed in {@link #insideBarrier} step.<a name="line.173"></a>
-<span class="sourceLineNo">174</span> */<a name="line.174"></a>
-<span class="sourceLineNo">175</span> @Override<a name="line.175"></a>
-<span class="sourceLineNo">176</span> public void acquireBarrier() throws ForeignException {<a name="line.176"></a>
-<span class="sourceLineNo">177</span> // NO OP<a name="line.177"></a>
-<span class="sourceLineNo">178</span> }<a name="line.178"></a>
-<span class="sourceLineNo">179</span><a name="line.179"></a>
-<span class="sourceLineNo">180</span> /**<a name="line.180"></a>
-<span class="sourceLineNo">181</span> * do a flush snapshot of every region on this rs from the target table.<a name="line.181"></a>
-<span class="sourceLineNo">182</span> */<a name="line.182"></a>
-<span class="sourceLineNo">183</span> @Override<a name="line.183"></a>
-<span class="sourceLineNo">184</span> public byte[] insideBarrier() throws ForeignException {<a name="line.184"></a>
-<span class="sourceLineNo">185</span> flushSnapshot();<a name="line.185"></a>
-<span class="sourceLineNo">186</span> return new byte[0];<a name="line.186"></a>
+<span class="sourceLineNo">170</span><a name="line.170"></a>
+<span class="sourceLineNo">171</span> // wait for everything to complete.<a name="line.171"></a>
+<span class="sourceLineNo">172</span> LOG.debug("Flush Snapshot Tasks submitted for " + regions.size() + " regions");<a name="line.172"></a>
+<span class="sourceLineNo">173</span> try {<a name="line.173"></a>
+<span class="sourceLineNo">174</span> taskManager.waitForOutstandingTasks();<a name="line.174"></a>
+<span class="sourceLineNo">175</span> } catch (InterruptedException e) {<a name="line.175"></a>
+<span class="sourceLineNo">176</span> LOG.error("got interrupted exception for " + getMemberName());<a name="line.176"></a>
+<span class="sourceLineNo">177</span> throw new ForeignException(getMemberName(), e);<a name="line.177"></a>
+<span class="sourceLineNo">178</span> }<a name="line.178"></a>
+<span class="sourceLineNo">179</span> }<a name="line.179"></a>
+<span class="sourceLineNo">180</span><a name="line.180"></a>
+<span class="sourceLineNo">181</span> /**<a name="line.181"></a>
+<span class="sourceLineNo">182</span> * do nothing, core of snapshot is executed in {@link #insideBarrier} step.<a name="line.182"></a>
+<span class="sourceLineNo">183</span> */<a name="line.183"></a>
+<span class="sourceLineNo">184</span> @Override<a name="line.184"></a>
+<span class="sourceLineNo">185</span> public void acquireBarrier() throws ForeignException {<a name="line.185"></a>
+<span class="sourceLineNo">186</span> // NO OP<a name="line.186"></a>
<span class="sourceLineNo">187</span> }<a name="line.187"></a>
<span class="sourceLineNo">188</span><a name="line.188"></a>
<span class="sourceLineNo">189</span> /**<a name="line.189"></a>
-<span class="sourceLineNo">190</span> * Cancel threads if they haven't finished.<a name="line.190"></a>
+<span class="sourceLineNo">190</span> * do a flush snapshot of every region on this rs from the target table.<a name="line.190"></a>
<span class="sourceLineNo">191</span> */<a name="line.191"></a>
<span class="sourceLineNo">192</span> @Override<a name="line.192"></a>
-<span class="sourceLineNo">193</span> public void cleanup(Exception e) {<a name="line.193"></a>
-<span class="sourceLineNo">194</span> LOG.info("Aborting all online FLUSH snapshot subprocedure task threads for '"<a name="line.194"></a>
-<span class="sourceLineNo">195</span> + snapshot.getName() + "' due to error", e);<a name="line.195"></a>
-<span class="sourceLineNo">196</span> try {<a name="line.196"></a>
-<span class="sourceLineNo">197</span> taskManager.cancelTasks();<a name="line.197"></a>
-<span class="sourceLineNo">198</span> } catch (InterruptedException e1) {<a name="line.198"></a>
-<span class="sourceLineNo">199</span> Thread.currentThread().interrupt();<a name="line.199"></a>
-<span class="sourceLineNo">200</span> }<a name="line.200"></a>
-<span class="sourceLineNo">201</span> }<a name="line.201"></a>
-<span class="sourceLineNo">202</span><a name="line.202"></a>
-<span class="sourceLineNo">203</span> /**<a name="line.203"></a>
-<span class="sourceLineNo">204</span> * Hooray!<a name="line.204"></a>
-<span class="sourceLineNo">205</span> */<a name="line.205"></a>
-<span class="sourceLineNo">206</span> public void releaseBarrier() {<a name="line.206"></a>
-<span class="sourceLineNo">207</span> // NO OP<a name="line.207"></a>
-<span class="sourceLineNo">208</span> }<a name="line.208"></a>
-<span class="sourceLineNo">209</span><a name="line.209"></a>
-<span class="sourceLineNo">210</span>}<a name="line.210"></a>
+<span class="sourceLineNo">193</span> public byte[] insideBarrier() throws ForeignException {<a name="line.193"></a>
+<span class="sourceLineNo">194</span> flushSnapshot();<a name="line.194"></a>
+<span class="sourceLineNo">195</span> return new byte[0];<a name="line.195"></a>
+<span class="sourceLineNo">196</span> }<a name="line.196"></a>
+<span class="sourceLineNo">197</span><a name="line.197"></a>
+<span class="sourceLineNo">198</span> /**<a name="line.198"></a>
+<span class="sourceLineNo">199</span> * Cancel threads if they haven't finished.<a name="line.199"></a>
+<span class="sourceLineNo">200</span> */<a name="line.200"></a>
+<span class="sourceLineNo">201</span> @Override<a name="line.201"></a>
+<span class="sourceLineNo">202</span> public void cleanup(Exception e) {<a name="line.202"></a>
+<span class="sourceLineNo">203</span> LOG.info("Aborting all online FLUSH snapshot subprocedure task threads for '"<a name="line.203"></a>
+<span class="sourceLineNo">204</span> + snapshot.getName() + "' due to error", e);<a name="line.204"></a>
+<span class="sourceLineNo">205</span> try {<a name="line.205"></a>
+<span class="sourceLineNo">206</span> taskManager.cancelTasks();<a name="line.206"></a>
+<span class="sourceLineNo">207</span> } catch (InterruptedException e1) {<a name="line.207"></a>
+<span class="sourceLineNo">208</span> Thread.currentThread().interrupt();<a name="line.208"></a>
+<span class="sourceLineNo">209</span> }<a name="line.209"></a>
+<span class="sourceLineNo">210</span> }<a name="line.210"></a>
+<span class="sourceLineNo">211</span><a name="line.211"></a>
+<span class="sourceLineNo">212</span> /**<a name="line.212"></a>
+<span class="sourceLineNo">213</span> * Hooray!<a name="line.213"></a>
+<span class="sourceLineNo">214</span> */<a name="line.214"></a>
+<span class="sourceLineNo">215</span> public void releaseBarrier() {<a name="line.215"></a>
+<span class="sourceLineNo">216</span> // NO OP<a name="line.216"></a>
+<span class="sourceLineNo">217</span> }<a name="line.217"></a>
+<span class="sourceLineNo">218</span><a name="line.218"></a>
+<span class="sourceLineNo">219</span>}<a name="line.219"></a>