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https://jira.jboss.org/browse/ISPN-663?page=com.atlassian.jira.plugin.sys...
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Trustin Lee commented on ISPN-663:
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I observed that store() is also called in 4.0 if I increase the length of the test loop
from 1000 to 10000000. However, 4.0 ends up with OutOfMemoryError with the increased loop
count while 4.2 passes the test with minimal heap expansion.
This experiment revealed another difference: 4.0 uses SimpleDataContainer which uses
ConcurrentHashMap. 4.2 uses DefaultDataContainer which uses BoundConcurrentHashMap.
BoundConcurrentHashMap calls eviction listener directly, which triggers
PassivationManagerImpl.passivate() (this eventually triggers store()), while neither
ConcurrentHashMap nor SimpleDataContainer does any eviction / passivation. Instead, 4.0
uses a ScheduledThreadPoolExecutor to run eviction / passivation in background.
Using ScheduledThreadPoolExecutor for eviction sounds somewhat risky because passivation
might not catch up very fast in-memory put()s as demonstrated by the test. Maybe
that's why 4.1 changed how eviction works? This answers the first question. To fix
this issue:
1) CacheStore could provide a batch store operation such as
CacheStore.store(InternalCacheEntry[] entries) and let user configure batched passivation
(e.g. passivate every 128 entries) OR
2) Run eviction in a background thread as before but make sure the task queue does not
grow, using a small bounded queue OR
3) Make (1) and (2) configurable
Maybe in 5.0?
Let me continue investigating why it is still 5~10 times slower without passivation.
Eviction with passivation using JdbmCacheStore is 100 times slower in
4.1 vs 4.0
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Key: ISPN-663
URL:
https://jira.jboss.org/browse/ISPN-663
Project: Infinispan
Issue Type: Bug
Components: Eviction, Loaders and Stores
Affects Versions: 4.1.0.Final
Environment: Win32 JRE 1.6.0_21
Reporter: Paul Nardone
Assignee: Trustin Lee
Fix For: 4.2.0.BETA1, 4.2.0.Final
Attachments: InfinispanPassivationTest.java
Eviction with passivation enabled using the JdbmCacheStore appears to be significantly
slower in 4.1.0.FINAL vs 4.0.0.FINAL.
The degredation in performance is so signficant to make it impossible to use
The performance issue seems to due as the JdbmCacheStore synching the filesystem via
FileDescriptor.sync() or similar which occurs during every object passivation and each
passivation occurs as a new object is added beyond the EvictionMaxEntries capacity.
The attached test inserts 1000 values into two caches
Both caches use a JdbmCacheStore and LRU
PASSIVATIONLRU10 runs with cache with EvictionMaxEntries 10
PASSIVATIONLRU1000 runs with cache with EvictionMaxEntries 1000
4.1.0.FINAL
PASSIVATIONLRU10 Time Taken : 51704
PASSIVATIONLRU1000 Time Taken : 4484
4.0.0.FINAL
PASSIVATIONLRU10 Time Taken : 281
PASSIVATIONLRU1000 Time Taken : 141
4.2.0.ALPHA2
PASSIVATIONLRU10 Time Taken : 51047
PASSIVATIONLRU1000 Time Taken : 5156
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