Details
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New Feature
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Status: Closed
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Major
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Resolution: Fixed
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0.99.0
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None
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Reviewed
Description
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:
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
External will look something like:
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