Now, after restarting node, we have only cold caches, which at first requests
to them will gradually load data from disks, which can slow down first calls to
them.
If node has more RAM than data on disk, then they can be loaded at start
"warmup", thereby solving the issue of slowdowns during first calls to caches.
I suggest adding a warmup phase after recovery here [1] after [2], before
descovery.
I suggest adding a new interface:
package org.apache.ignite.internal.processors.cache;
import org.apache.ignite.IgniteCheckedException;
import org.apache.ignite.internal.IgniteInternalFuture;
import org.jetbrains.annotations.Nullable;
/**
* Interface for warming up cache.
*/
public interface CacheWarmup {
/**
* Warmup cache.
*
* @param cacheCtx Cache context.
* @return Future cache warmup.
* @throws IgniteCheckedException if failed.
*/
@Nullable IgniteInternalFuture<?> process(GridCacheContext cacheCtx) throws
IgniteCheckedException;
}
Which will allow to warm up caches in parallel and asynchronously. Warmup phase
will end after all IgniteInternalFuture for all caches isDone.
Also adding the ability to customize via methods:
org.apache.ignite.configuration.IgniteConfiguration#setDefaultCacheWarmup
org.apache.ignite.configuration.CacheConfiguration#setCacheWarmup
Which will allow for each cache to set implementation of cache warming up, both
for a specific cache, and for all if necessary.
I suggest adding an implementation of SequentialWarmup that will use [3].
Questions, suggestions, comments?
[1] -
org.apache.ignite.internal.processors.cache.GridCacheProcessor.CacheRecoveryLifecycle#afterLogicalUpdatesApplied
[2] -
org.apache.ignite.internal.processors.cache.GridCacheProcessor.CacheRecoveryLifecycle#restorePartitionStates
[3] -
org.apache.ignite.internal.processors.cache.IgniteCacheOffheapManager.CacheDataStore#preload
