Priority: Critical - P2
Affects Version/s: 3.2.10, 3.4.2
Fix Version/s: None
We run a cluster with 27 shards and each application uses a local mongos to connect to it. We have the balancer stopped.
We often see Exception for querys to collections which are sharded. Everytime there is a change to shard version of the collection, our PHP clients report an error on a simple find operation. Sofar we have never seen an exception for our non PHP clients.
It seems that this issue was introduced with mongodb version 3.2.x, but we can also reproduce it on 3.4.2 in our dev environment.
To reproduce it in our dev environemnt I started to shard a collection, but I could also move a chunk or split a chunk. I choose this collection because we see problems for querys to this collection in production which runs version 3.2.10 and we hadn't sharded it in our dev environment so far (very small in dev).
There are no errors in router.log
Before we sharded the collection our PHP application showed no errors.
After sharding our PHP client reports:
To fix the router reporting this exception on a query we found 3 ways:
- restart router
- do a find query on this collection via mongo shell. (tested with version 3.4.2 only)
Could it be that routers only trigger chunk information updates when a client does an operation on a collection? -> this is broken for php driver only?
Since we can reproduce it in our dev environment with version 3.4.2, we our glad to debug this with your help.
This is a blocker for us in production since even the balancer is off, autosplits also cause this issue.