Uploaded image for project: 'Cassandra'
  1. Cassandra
  2. CASSANDRA-12860

Nodetool repair fragile: cannot properly recover from single node failure. Has to restart all nodes in order to repair again

    XMLWordPrintableJSON

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Urgent
    • Resolution: Duplicate
    • Fix Version/s: None
    • Component/s: None
    • Labels:
      None
    • Environment:

      CentOS 6.7, Java HotSpot(TM) 64-Bit Server VM (build 25.102-b14, mixed mode), Cassandra 3.5.0, fresh install

    • Severity:
      Critical

      Description

      Summary of symptom:

      • Set up is a multi-region cluster in AWS (5 regions). Each region has at least 4 hosts with RF=1/2 number of nodes, using V-nodes (256)
      • How to reproduce:
        • On node A, start this repair job (again we are running fresh 3.5.0):
          nohup sudo nodetool repair -j 2 -pr -full myks > /tmp/repair.log 2>&1 &
        • Job starts fine, reporting progress like
          [2016-10-28 22:37:52,692] Starting repair command #1, repairing keyspace myks with repair options (parallelism: parallel, primary range: true, incremental: false, job threads: 2, ColumnFamilies: [], dataCenters: [], hosts: [], # of ranges: 256)
          [2016-10-28 22:38:35,099] Repair session 36f13450-9d5f-11e6-8bf7-a9f47ff986a9 for range [(4029874034937227774,4033949979656106020]] finished (progress: 1%)
          [2016-10-28 22:38:38,769] Repair session 36f30910-9d5f-11e6-8bf7-a9f47ff986a9 for range [(-2395606719402271267,-2394525508513518837]] finished (progress: 1%)
          [2016-10-28 22:38:48,521] Repair session 36f3f370-9d5f-11e6-8bf7-a9f47ff986a9 for range [(-5223108861718702793,-5221117649630514419]] finished (progress: 2%)
          
        • Then manually shutdown another node (node B) in the same region (haven't tried with other region yet but expect the same behavior from past experience)
        • Shortly after that seeing this message from job log (as well as in system.log) on node A:
          [2016-10-28 22:41:46,268] Repair session 37088ce1-9d5f-11e6-8bf7-a9f47ff986a9 for range [(-928974038666914990,-927967994563261540]] failed with error Endpoint /node_B_ip died (progress: 51%)
          
        • From this point on, repair job seems to hang:
          • no further messages from job log
          • nor any related messages in system.log
          • CPU stayed low (low single digit percent of 1 CPU)
        • After an hour (1hr), manually kill the repair jobs using "ps -eaf | grep repair"
        • Restart C* on node A
          • Verified system is up and no error messages in system.log
          • Also verified that there is no error messages from node B
        • After node A settles down (e.g. no new messages from system.log), restart the same repair job:
          nohup sudo nodetool repair -j 2 -pr -full myks > /tmp/repair.log 2>&1 &
        • Job failes pretty quickly, reporting error from more nodes B and K:
           <production>[ywu@cass-tm-1b-012.apse1.mashery.com ~]$ tail -f /tmp/repair.log 
          [2016-10-28 22:49:52,965] Starting repair command #1, repairing keyspace myks with repair options (parallelism: parallel, primary range: true, incremental: false, job threads: 2, ColumnFamilies: [], dataCenters: [], hosts: [], # of ranges: 256)
          [2016-10-28 22:50:15,839] Repair session e4180720-9d60-11e6-b2f9-cb9524b3c536 for range [(4029874034937227774,4033949979656106020]] failed with error [repair #e4180720-9d60-11e6-b2f9-cb9524b3c536 on myks/rtable, [(4029874034937227774,4033949979656106020]]] Validation failed in /node_K_ip (progress: 1%)
          [2016-10-28 22:50:17,158] Repair session e419dbe0-9d60-11e6-b2f9-cb9524b3c536 for range [(-2395606719402271267,-2394525508513518837]] failed with error [repair #e419dbe0-9d60-11e6-b2f9-cb9524b3c536 on myks/rtable, [(-2395606719402271267,-2394525508513518837]]] Validation failed in /node_B_ip (progress: 1%)
          [2016-10-28 22:50:18,256] Repair session e41b1460-9d60-11e6-b2f9-cb9524b3c536 for range [(-5223108861718702793,-5221117649630514419]] failed with error [repair #e41b1460-9d60-11e6-b2f9-cb9524b3c536 on myks/rtable, [(-5223108861718702793,-5221117649630514419]]] Validation failed in /node_B_ip (progress: 2%)
          
        • On the said nodes (B and K), seeing similar errors:
          ERROR [ValidationExecutor:5] 2016-10-28 22:58:45,307 CompactionManager.java:1320 - Cannot start multiple repair sessions over the same sstables
          ERROR [ValidationExecutor:5] 2016-10-28 22:58:45,307 Validator.java:261 - Failed creating a merkle tree for [repair #14378ec0-9d62-11e6-ab75-cd4d64a01b02 on myks/atable, [(4029874034937227774,4033949979656106020]]], /52.220.127.190 (see log for details)
          INFO  [AntiEntropyStage:1] 2016-10-28 22:58:45,307 Validator.java:274 - [repair #14378ec0-9d62-11e6-ab75-cd4d64a01b02] Sending completed merkle tree to /52.220.127.190 for myks.xtable
          ERROR [ValidationExecutor:5] 2016-10-28 22:58:45,308 CassandraDaemon.java:195 - Exception in thread Thread[ValidationExecutor:5,1,main]
          java.lang.RuntimeException: Cannot start multiple repair sessions over the same sstables
                  at org.apache.cassandra.db.compaction.CompactionManager.getSSTablesToValidate(CompactionManager.java:1321) ~[apache-cassandra-3.5.0.jar:3.5.0]
                  at org.apache.cassandra.db.compaction.CompactionManager.doValidationCompaction(CompactionManager.java:1211) ~[apache-cassandra-3.5.0.jar:3.5.0]
                  at org.apache.cassandra.db.compaction.CompactionManager.access$700(CompactionManager.java:81) ~[apache-cassandra-3.5.0.jar:3.5.0]
                  at org.apache.cassandra.db.compaction.CompactionManager$11.call(CompactionManager.java:841) ~[apache-cassandra-3.5.0.jar:3.5.0]
                  at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_102]
                  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) ~[na:1.8.0_102]
                  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_102]
                  at java.lang.Thread.run(Thread.java:745) [na:1.8.0_102]
          INFO  [AntiEntropyStage:1] 2016-10-28 22:58:45,318 Validator.java:274 - [repair #14378ec0-9d62-11e6-ab75-cd4d64a01b02] Sending completed merkle tree to /52.220.127.190 for myks.ytable
          
        • At this point, we are back to where we were: kill the repair job on node A, then restart C* on BOTH nodes A and K, but still seeing the same exceptions except sometimes they are on other servers all over the ring.
      • Business impact: I am in the process of launch a Cassandra based production system but I have to hold back now because how fragile repair is. And I am told by many sources that I have to rely on periodical repair jobs to fix data inconsistencies.
      • The only work around was to rolling restart the Cassandra server on ALL nodes in the entire cluster
        • Then the repair job can proceed without any error

        Attachments

          Issue Links

            Activity

              People

              • Assignee:
                Unassigned
                Reporter:
                bing1wu Bing Wu
              • Votes:
                0 Vote for this issue
                Watchers:
                5 Start watching this issue

                Dates

                • Created:
                  Updated:
                  Resolved: