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  1. HBase
  2. HBASE-10785

Metas own location should be cached

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Details

    • Improvement
    • Status: Closed
    • Major
    • Resolution: Fixed
    • None
    • 0.99.0, hbase-10070
    • None
    • None
    • Reviewed

    Description

      With ROOT table gone, we no longer cache the location of the meta table (in MetaCache) in 96+. I've checked 94 code, and there we cache meta, but not root.

      However, not caching the metas own location means that we are doing a zookeeper request every time we want to look up a regions location from meta. This means that there is a significant spike in zk requests whenever a region server goes down.

      This affects trunk,0.98 and 0.96 as well as hbase-10070 branch. I've discovered the issue in hbase-10070 because of the integration test (HBASE-10572) results in 150K requests to zk in 10min.

      A thread dump from one of the runs have 100+ threads from client in this stack trace: 

      	"TimeBoundedMultiThreadedReaderThread_20" prio=10 tid=0x00007f852c2f2000 nid=0x57b6 in Object.wait() [0x00007f85059e7000]
	   java.lang.Thread.State: WAITING (on object monitor)
		at java.lang.Object.wait(Native Method)
		at java.lang.Object.wait(Object.java:503)
		at org.apache.zookeeper.ClientCnxn.submitRequest(ClientCnxn.java:1309)
		- locked <0x00000000ea71aa78> (a org.apache.zookeeper.ClientCnxn$Packet)
		at org.apache.zookeeper.ZooKeeper.getData(ZooKeeper.java:1149)
		at org.apache.hadoop.hbase.zookeeper.RecoverableZooKeeper.getData(RecoverableZooKeeper.java:337)
		at org.apache.hadoop.hbase.zookeeper.ZKUtil.getData(ZKUtil.java:684)
		at org.apache.hadoop.hbase.zookeeper.ZKUtil.blockUntilAvailable(ZKUtil.java:1853)
		at org.apache.hadoop.hbase.zookeeper.MetaRegionTracker.blockUntilAvailable(MetaRegionTracker.java:186)
		at org.apache.hadoop.hbase.client.ZooKeeperRegistry.getMetaRegionLocation(ZooKeeperRegistry.java:60)
		at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1126)
		at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1112)
		at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegionInMeta(ConnectionManager.java:1220)
		at org.apache.hadoop.hbase.client.ConnectionManager$HConnectionImplementation.locateRegion(ConnectionManager.java:1129)
		at org.apache.hadoop.hbase.client.RpcRetryingCallerWithReadReplicas.getRegionLocations(RpcRetryingCallerWithReadReplicas.java:321)
		at org.apache.hadoop.hbase.client.RpcRetryingCallerWithReadReplicas.call(RpcRetryingCallerWithReadReplicas.java:257)
		- locked <0x00000000e9bcf238> (a org.apache.hadoop.hbase.client.RpcRetryingCallerWithReadReplicas)
		at org.apache.hadoop.hbase.client.HTable.get(HTable.java:818)
		at org.apache.hadoop.hbase.util.MultiThreadedReader$HBaseReaderThread.queryKey(MultiThreadedReader.java:288)
		at org.apache.hadoop.hbase.util.MultiThreadedReader$HBaseReaderThread.readKey(MultiThreadedReader.java:249)
		at org.apache.hadoop.hbase.util.MultiThreadedReader$HBaseReaderThread.runReader(MultiThreadedReader.java:192)
		at org.apache.hadoop.hbase.util.MultiThreadedReader$HBaseReaderThread.run(MultiThreadedReader.java:150)

      Attachments

        1. hbase-10785_v3.patch
          3 kB
          Enis Soztutar
        2. hbase-10785_v2.patch
          4 kB
          Enis Soztutar
        3. hbase-10785_v1.patch
          3 kB
          Enis Soztutar
        4. 0034-HBASE-10785-Metas-own-location-should-be-cached.patch
          3 kB
          Enis Soztutar

        Issue Links

          is duplicated by

          Sub-task - The sub-task of the issue HBASE-11758 Meta region location should be cached

          • Major - Major loss of function.
          • Closed
          is related to

          Sub-task - The sub-task of the issue HBASE-10701 Cache invalidation improvements from client side

          • Major - Major loss of function.
          • Closed

          New Feature - A new feature of the product, which has yet to be developed. HBASE-10070 HBase read high-availability using timeline-consistent region replicas

          • Major - Major loss of function.
          • Closed

          Activity

            People

              enis Enis Soztutar
              enis Enis Soztutar
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              Dates

                Created:
                Updated:
                Resolved: