Disabling Storage Engines

[Elias Torres]

I was working through a deployment run and thought it would be good to disable all engines except the one I really need (read-only) but to my surprise all of the 'enable.ENGINE.disable=true' seemed to be ignored. VoldemortConfig seems to confirm that.

I know there's some new work on property reading, but does it include disabling of storage engines? 

-elias

[Jay Kreps]

Hi Elias,

I think you are working off trunk rather than one of the older
snapshots. Previously there was an enable.yxzengine = true flag for
each storage engine. Then we realized this was stupid because it meant
each storage engine had to be a part of voldemort and you couldn't
have a plugin engine.

To add this feature we changed it to work this way:

storage.configs=voldemort.store.bdb.BdbStorageConfiguration,
voldemort.store.readonly.RandomAccessFileStorageConfiguration,...

i.e. you add the full class name for all storage engines you want to
enable. The default is you get BDB, MySQL, memory, cache, and
read-only.

I haven't documented this well because it is only on trunk so far.

-Jay

[Elias Torres]

That's right. I'm working off trunk.

[2009-04-01 12:28:51,426] INFO Starting storage-service (voldemort.server.VoldemortService)

Exception in thread "main" voldemort.utils.ConfigurationException: Attempt to open store slop but bdb storage engine has not been enabled.

at voldemort.server.storage.StorageService.getStore(StorageService.java:196)

at voldemort.server.storage.StorageService.startInner(StorageService.java:125)

at voldemort.server.AbstractService.start(AbstractService.java:62)

at voldemort.server.VoldemortServer.startInner(VoldemortServer.java:121)

at voldemort.server.AbstractService.start(AbstractService.java:62)

at voldemort.server.VoldemortServer.main(VoldemortServer.java:177)

Is BDB required?

Thanks,

-Elias

[Geir Magnusson]

yes, it's required for config information.

geir

[Dain Sundstrom]

Shouldn't it be automatically added then? Or even better available
for the config information but use user stores.

-dain

[Elias Torres]

I figured, but I wanted this to be as lean and mean as possible. For example, if JVM crashes, then I have to make sure I remove lock, no?

-Elias

[Jay Kreps]

Yeah, I think this is a bug. The storage engine used for slop (if slop
is enabled) should be automatically started. I will file an issue.

-Jay