Disable Persistence
How can persistence be disabled?
Can the ep_engine be turned off?
What negative consequences would there be?
Hi mikew, We're having the same issue. Is there anyway we can disable the persistence or at-least clear the persistent cache when it comes up after failure (to avoid cache inconsistencies)
I'm not totally sure what your asking, but if use the Couchbase bucket the data that is in memory is always the most up to date data even if there are failures.
Hello,
I'm really interested by disabling the persistence : we are currently using memcached only but some features of couchbase could be really useful for us, specially the bucket resizing, the replication and the rebalancing (probably the cross-data-center replication too).
The drawback of persistence for us is the latency to restart a node, and the fact that it won't evict : this means for bad sized lifetime you can have you RAM full we only keys and slow requests due to disk fetches.
Is it a good idea to try disabling the persistence in that case? Do you have another solution?
Anyway how can I disable it to do some tests?
Thank you.
It is not possible to disable persistence with a Couchbase bucket. If you don't want persistence then w recommend using a memcached bucket.
I have a similar issue. I'm running a single-node of couchbase for a distributed cache. Redundancy and fail-over aren't needed. When I need to restart the couchbase service it takes 20 minutes to come back up. I can't use a memcached bucket because some of the objects put in cache are too large for memcached.
I've tried using cbflushctl command line tool without success. It would be great if there were some way to flush the cache before restarting the service or disable disk persistence all together.
Does anyone know of a way to decrease the amount of time it takes to restart the couchbase service?
Mikew, can you provide more info about this?
As dirty temporary solution, you can try to create virtual RAM disk and configure couchbase to write data into that virtual disk.
The way to stop persistence I was talking about was by using cbflushctl (now cbepctl) to stop it, but this won;t solve you problem because persistence will have to be resumed at some point. Couchbase 2.0 will add some improvements to make the warmup time faster and add some configurations so that you can enable the smallest warmup time currently possible. This type of warmup would only need to load meta data into memory.
If you do not need persistence then you should use the memcached bucket. This bucket type will not run with ep-engine and will not persist any data. Their is a way to stop persistence on a Couchbase bucket, but it can potentially cause many issues if used improperly and should not be turned off for extended periods of time. I can explain more if you need to use a Couchbase bucket.