[jira] [Created] (HBASE-9531) a command line (hbase shell) interface to retreive the replication metrics and show replication lag

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

Demai Ni created HBASE-9531:
-------------------------------

             Summary: a command line (hbase shell) interface to retreive the replication metrics and show replication lag
                 Key: HBASE-9531
                 URL: https://issues.apache.org/jira/browse/HBASE-9531
             Project: HBase
          Issue Type: New Feature
          Components: Replication
            Reporter: Demai Ni
            Assignee: Demai Ni


This jira is to provide a command line (hbase shell) interface to retreive the replication metrics info such as:ageOfLastShippedOp, timeStampsOfLastShippedOp, sizeOfLogQueue ageOfLastAppliedOp, and timeStampsOfLastAppliedOp. And also to provide a point of time info of the lag of replication(source only)

Understand that hbase is using Hadoop metrics(http://hbase.apache.org/metrics.html), which is a common way to monitor metric info. This Jira is to serve as a light-weight client interface, comparing to a completed(certainly better, but heavier)GUI monitoring package. I made the code works on 0.94.9 now, and like to use this jira to get opinions about whether the feature is valuable to other users/workshop. If so, I will build a trunk patch. 

All inputs are greatly appreciated. Thank you!

The overall design is to reuse the existing logic which supports hbase shell command 'status', and invent a new module, called ReplicationLoad.  In HRegionServer.buildServerLoad() , use the local replication service objects to get their loads  which could be wrapped in a ReplicationLoad object and then simply pass it to the ServerLoad. In ReplicationSourceMetrics and ReplicationSinkMetrics, a few getters and setters will be created, and ask Replication to build a "ReplicationLoad".  (many thanks to Jean-Daniel for his kindly suggestions through dev email list)

the replication lag will be calculated for source only, and use this formula: 
{code:title=Replication lag|borderStyle=solid}
	if sizeOfLogQueue != 0 then max(ageOfLastShippedOp, (current time - timeStampsOfLastShippedOp)) //err on the large side
	else if (current time - timeStampsOfLastShippedOp) < 2* ageOfLastShippedOp then lag = ageOfLastShippedOp // last shipped happen recently 
		else lag = 0 // last shipped may happens last night, so NO real lag although ageOfLastShippedOp is non-zero
{code}

External will look something like:
{code:title=status 'replication'|borderStyle=solid}
hbase(main):001:0> status 'replication'
version 0.94.9
3 live servers
    hdtest017.svl.ibm.com:
        SOURCE:PeerID=1, ageOfLastShippedOp=14, sizeOfLogQueue=0, timeStampsOfLastShippedOp=Wed Sep 04 14:49:48 PDT 2013
        SINK  :AgeOfLastAppliedOp=0, TimeStampsOfLastAppliedOp=Wed Sep 04 14:48:48 PDT 2013
    hdtest018.svl.ibm.com:
        SOURCE:PeerID=1, ageOfLastShippedOp=0, sizeOfLogQueue=0, timeStampsOfLastShippedOp=Wed Sep 04 14:48:48 PDT 2013
        SINK  :AgeOfLastAppliedOp=14, TimeStampsOfLastAppliedOp=Wed Sep 04 14:50:59 PDT 2013
    hdtest015.svl.ibm.com:
        SOURCE:PeerID=1, ageOfLastShippedOp=0, sizeOfLogQueue=0, timeStampsOfLastShippedOp=Wed Sep 04 14:48:48 PDT 2013
        SINK  :AgeOfLastAppliedOp=0, TimeStampsOfLastAppliedOp=Wed Sep 04 14:48:48 PDT 2013

hbase(main):002:0> status 'replication','source'
version 0.94.9
3 live servers
    hdtest017.svl.ibm.com:
        SOURCE:PeerID=1, ageOfLastShippedOp=14, sizeOfLogQueue=0, timeStampsOfLastShippedOp=Wed Sep 04 14:49:48 PDT 2013
    hdtest018.svl.ibm.com:
        SOURCE:PeerID=1, ageOfLastShippedOp=0, sizeOfLogQueue=0, timeStampsOfLastShippedOp=Wed Sep 04 14:48:48 PDT 2013
    hdtest015.svl.ibm.com:
        SOURCE:PeerID=1, ageOfLastShippedOp=0, sizeOfLogQueue=0, timeStampsOfLastShippedOp=Wed Sep 04 14:48:48 PDT 2013

hbase(main):003:0> status 'replication','sink'
version 0.94.9
3 live servers
    hdtest017.svl.ibm.com:
        SINK  :AgeOfLastAppliedOp=0, TimeStampsOfLastAppliedOp=Wed Sep 04 14:48:48 PDT 2013
    hdtest018.svl.ibm.com:
        SINK  :AgeOfLastAppliedOp=14, TimeStampsOfLastAppliedOp=Wed Sep 04 14:50:59 PDT 2013
    hdtest015.svl.ibm.com:
        SINK  :AgeOfLastAppliedOp=0, TimeStampsOfLastAppliedOp=Wed Sep 04 14:48:48 PDT 2013

hbase(main):003:0> status 'replication','lag' 
version 0.94.9
3 live servers
    hdtest017.svl.ibm.com: lag = 0
    hdtest018.svl.ibm.com: lag = 14
    hdtest015.svl.ibm.com: lag = 0
{code}



--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira