Hello , MongoDB Team.
Our Sharded Cluster has 3 shards and each shard contains 3 members.
But , specific 1 member of each shard tends to show high disk usage.
(MongoDB binary : Community Server)
And, it seems not to be associated which is Primary or Secondary.
Here is disk usage on each shard :
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< Shard 1>
- Member 1-1 (Primary)
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 3.1T 2.9T 140G 96% /home
- Member 1-2 (Secondary)
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 3.1T 2.3T 754G 76% /home
- Member 1-3 (Secondary)
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 3.1T 2.3T 754G 76% /home
< Shard 2>
- Member 2-1 (Primary)
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 3.1T 2.3T 776G 75% /home
- Member 2-2 (Secondary)
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 3.1T 2.9T 157G 95% /home
- Member 2-3 (Secondary)
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 3.1T 2.3T 773G 75% /home
< Shard 3>
- Member 3-1 (Primary)
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 3.1T 2.9T 154G 96% /home
- Member 3-2 (Secondary)
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 3.1T 2.3T 758G 76% /home
- Member 3-3 (Secondary)
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 3.1T 2.3T 759G 76% /home
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To ask investigation , I was seeking where this difference was made.
Total usage of user-made database was almost the same but database ‘local’ was not.
specific only one member of a shard shows high usage on ‘local’ DB.
I think this was the reason
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< Shard 1> ## user-made DB : noteDB_v2
- Member 1-1 (Primary)
654G local
2.2T noteDB_v2
- Member 1-2 (Secondary)
38G local
2.2T noteDB_v2
- Member 1-3 (Secondary)
38G local
2.2T noteDB_v2
< Shard 2>
- Member 2-1 (Secondary)
38G local
2.2T noteDB_v2
- Member 2-2 (Primary)
655G local
2.2T noteDB_v2
- Member 2-3 (Secondary)
38G local
2.2T noteDB_v2
< Shard 3>
- Member 3-1 (Primary)
646G local
2.2T noteDB_v2
- Member 3-2 (Secondary)
38G local
2.2T noteDB_v2
- Member 3-3 (Secondary)
39G local
2.2T noteDB_v2
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I need to know why it has happened
and need to get the solution.
(
. Cluster Establishment :
3 Routers
3 Config server members
3 Shard (3 members each / No arbiter (PSS))
. Version : MongoDB 4.4.22 (Community Server)
I asked this via MongoDB Customer Support first, but they told me any questions with Commnunity server will be proceeded here .
)
Thank you.