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  1. Core Server
  2. SERVER-3456

Running fsync+lock on config server during backup results in blocked inserts

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    Details

    • Type: Question
    • Status: Closed
    • Priority: Major - P3
    • Resolution: Won't Fix
    • Affects Version/s: 1.8.2
    • Fix Version/s: None
    • Component/s: Concurrency, Sharding
    • Labels:
    • Environment:
      Ubuntu 10.10

      Description

      The documentation recommends doing an fsync+lock of a config server when taking a backup of a sharded cluster, but all of my tests using this method seem to result in blocked inserts after a few seconds ( I think when it needs to split the chunk ).

      http://www.mongodb.org/display/DOCS/Backing+Up+Sharded+Cluster

      Environment
      Ubuntu 10.10
      MongoDB 1.8.2
      3 shards
      3 replica set members per shard
      3 config servers
      1 mongos
      chunksize=1 to force splits earlier

      Steps to reproduce
      1. Stop balancer
      2. Verify balancer stopped
      3. Run test script to generate inserts
      4. fsync+lock config server
      5. Wait a few seconds for block

      I think I can work around the issue by shutting down the config database instead of doing an fsync and lock, but wanted to check to see whether or not this was a bug or just something missing in the documentation.

      Thanks

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              Assignee:
              Unassigned Unassigned
              Reporter:
              jlee Jeff lee
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