[jira] [Work started] (HBASE-11617) AgeOfLastAppliedOp in MetricsSink got increased when no new replication sink OP

["Demai Ni (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HBASE-11617?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Work on HBASE-11617 started by Demai Ni.

> AgeOfLastAppliedOp in MetricsSink got increased when no new replication sink OP 
> --------------------------------------------------------------------------------
>
>                 Key: HBASE-11617
>                 URL: https://issues.apache.org/jira/browse/HBASE-11617
>             Project: HBase
>          Issue Type: Bug
>          Components: Replication
>    Affects Versions: 0.98.2
>            Reporter: Demai Ni
>            Assignee: Demai Ni
>            Priority: Minor
>             Fix For: 0.99.0, 0.98.5, 2.0.0
>
>
> AgeOfLastAppliedOp in MetricsSink.java is to indicate the time an edit sat in the 'replication queue' before it got replicated(aka applied)
> {code}
>   /**
>    * Set the age of the last applied operation
>    *
>    * @param timestamp The timestamp of the last operation applied.
>    * @return the age that was set
>    */
>   public long setAgeOfLastAppliedOp(long timestamp) {
>     lastTimestampForAge = timestamp;
>     long age = System.currentTimeMillis() - lastTimestampForAge;
>     rms.setGauge(SINK_AGE_OF_LAST_APPLIED_OP, age);
>     return age;
>   } 
> {code}
> In the following scenario:
> 1) at 7:00am a sink op is applied, and the SINK_AGE_OF_LAST_APPLIED_OP is
> set for example 100ms;
> 2) and then NO new Sink op occur.
> 3) when a refreshAgeOfLastAppliedOp() is invoked at 8:00am. Instead of
> return the 100ms, the AgeOfLastAppliedOp become 1hour + 100ms, 
> It was because that refreshAgeOfLastAppliedOp() get invoked periodically by getStats(). 
> proposed fix: 
> {code}
> --- hbase-server/src/main/java/org/apache/hadoop/hbase/replication/regionserver/MetricsSink.java
> +++ hbase-server/src/main/java/org/apache/hadoop/hbase/replication/regionserver/MetricsSink.java
> @@ -35,6 +35,7 @@ public class MetricsSink {
>  
>    private MetricsReplicationSource rms;
>    private long lastTimestampForAge = System.currentTimeMillis();
> +  private long age = 0;
>  
>    public MetricsSink() {
>      rms = CompatibilitySingletonFactory.getInstance(MetricsReplicationSource.class);
> @@ -47,8 +48,12 @@ public class MetricsSink {
>     * @return the age that was set
>     */
>    public long setAgeOfLastAppliedOp(long timestamp) {
> -    lastTimestampForAge = timestamp;
> -    long age = System.currentTimeMillis() - lastTimestampForAge;
> +    if (lastTimestampForAge != timestamp) {
> +      lastTimestampForAge = timestamp;
> +      this.age = System.currentTimeMillis() - lastTimestampForAge;
> +    } else {
> +      this.age = 0;
> +    }
>      rms.setGauge(SINK_AGE_OF_LAST_APPLIED_OP, age);
>      return age;
>    }
> {code}
> detail discussion in [dev@hbase  | http://mail-archives.apache.org/mod_mbox/hbase-dev/201407.mbox/%3CCAOEq2C5BKMXAM2Fv4LGVb_Ktek-Pm%3DhjOi33gSHX-2qHqAou6w%40mail.gmail.com%3E ]



--
This message was sent by Atlassian JIRA
(v6.2#6252)