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  1. Core Server
  2. SERVER-36017

Balancer doesn't migrate chunks

    • Type: Icon: Question Question
    • Resolution: Done
    • Priority: Icon: Major - P3 Major - P3
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    • Affects Version/s: 3.6.5
    • Component/s: Sharding
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    • 3
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      We have upgraded MongoDB sharded cluster from 2.0 to 3.6 in the past 6 months.

      And then, we enabled balancer, but no chunk migration occurred for 5 hours.

      After we enabled blancer, primary config server logged,

      2018-XX-XXT09:36:39.007+0900 I SHARDING [Balancer] Refreshing chunks for collection db.sharded-collection based on version 0|0||000000000000000000000000
      2018-XX-XXT09:36:39.103+0900 I SHARDING [ConfigServerCatalogCacheLoader-1] Refresh for collection db.sharded-collection took 95 ms aand found version 7|27819||5a66b9b7eb81557948d33b6f  
       
      2018-XX-XXT13:50:29.159+0900 I SHARDING [Balancer] Refreshing chunks for collection db.sharded-collection based on version 7|27819||5a66b9b7eb81557948d33b6f
      2018-XX-XXT13:50:29.164+0900 I SHARDING [ConfigServerCatalogCacheLoader-2] Refresh for collection db.sharded-collection took 4 ms and found version 7|27819||5a66b9b7eb81557948d33b6f  
      
      

       Our dev MongoDB cluster's primary config server logged "version 22" and it migrates chunks well.

      Currently, balancer is disabled. We have never used balancer before. So, chunks are quite unevenly distributed.

      I attached our server's stats. No jumbo chunk exists. Any guesses on what blocks balancer's chunk migration and possible solution?

       

            Assignee:
            ramon.fernandez@mongodb.com Ramon Fernandez Marina
            Reporter:
            Changmin Changmin Keum [X]
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              Created:
              Updated:
              Resolved: