[SERVER-54683] Running shard with standalone Mongod and config server with single node replica Created: 21/Feb/21  Updated: 06/Dec/22  Resolved: 22/Feb/21

Status: Closed
Project: Core Server
Component/s: Sharding
Affects Version/s: 4.9.0-alpha3, 4.9.0-alpha4
Fix Version/s: None

Type: Question Priority: Major - P3
Reporter: Viraj Thakrar Assignee: Backlog - Triage Team
Resolution: Done Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Related
Assigned Teams:
Server Triage
Participants:

 Description   

This is how my architecture looks like for testing / bench-marking purpose.

  1. Config server running with single node replica set (on x86 build)
  2. Single mongos (on x86 build)
  3. 4 Shards running with standalone mongods (on different build)

I've imported 10M documents and enabled hashed Sharding. With this 10M total data size reaches up-to ~1.3 GB.  As I've applied hashed Sharding, it should balance chunk well and should start migrating the chunks over to the different shards.  But after waiting over longer period of time, it hasn't migrate single chunk over. 

When I've converted standalone mongods to single node replica set on all of the shards, it started migrating chunks and after some time, it has precisely balanced the chunks across all shards. 

 

My question is: 

  1. was running standalone mongod on each shard was an issue?
  2. Running sharded cluster components in different environments  (mongos and config on one build and mongod in another build) would be causing this issue?

Thanks!
Viraj



 Comments   
Comment by Viraj Thakrar [ 01/Mar/21 ]

Hi Eric,

Thank you for responding. 

Yes it is working fine with different builds. 

Best,

Viraj

Comment by Eric Sedor [ 22/Feb/21 ]

Hi Viraj,

It is true that shards must be replica sets. Ideally there would not be an issue with different underlying system builds.

I'm going to close this ticket but if you run into trouble on a supported configuration, we'd be happy to look deeper.

Sincerely,
Eric

Generated at Thu Feb 08 05:34:12 UTC 2024 using Jira 9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66.