upon upgrading and rebooting nodes from our memcached cluster, I noticed that seahub apparently stops working whenerver one of the memcached nodes is unavailable. Which leaves me puzzled as I would expect a memcached-cluster setup to prevent exactly this? Anyone experiencing the same thing? Is this maybe a misconfiguration on our side?
Thanks in advance!
Memcached Cluster support was dropped some time ago because they couldn’t fix certain problems and simply declared that it is not needed. … Which is not true, they simply did not seem to have this tested in a proper manner otherwise they would know that a memcached node failover (since clusters are not supported) causes serious issues in a Seafile cluster, especially with many connections/users.
A suitable solution would be to support redis, which is easy to cluster, a more modern approach and widely used for exactly this purpose in modern applications. It also scales a lot better than memcached.
Can you please elaborate on the future plans for this? A proper caching solution is required.
The same goes for CE as to replace memcached entirely or at least give the option to use redis.
Not providing a cluster solution for a cached backend makes the whole Seafile cluster not a real HA cluster.
When the memcached node breaks off the cluster crashes and users are loosing connections, Seahub is unresponsive and requires a service restart to start working properly again. This causes service interruptions and user support requests for they see error messages.
Thanks in advance for providing a proper caching cluster backend integration!
Redis support will be added in version 9.0.
This is really good news. Especially enterprise customers will be very happy about it
We use yrmcds for this. Worked without problems for years and manages the failover automatically.