[2.1] 1584256: Detach consumers from persistence context to avoid OOM - ENT-583 #2016
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Code itself looks fine; though I'm curious if there are other consequences of blasting the entire context and unlinking some entities. Specifically, though the processPoolUpdates method.
There's an extra bit of code that can be removed from deleteExpiredPoolsImpl that flushes (and intends to clear) which can be removed entirely due to the extra flushing in deletePools
| // Recalculate status for affected consumers | ||
| for (List<String> subList : Lists.partition(consumers, 1000)) { | ||
| for (String consumerId : subList) { | ||
| Consumer consumer = consumerCurator.get(consumerId); |
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Since we've blasted the Hibernate cache, this is hitting the DB for each consumer. I imagine we'd see some substantial gains if we bulked up the lookup for the entire sublist of consumers. Given our concerns with memory, this may mean dropping the size of the partitioning down from 1000 (and maybe converting that to a constant while we're at it), but any bulking at all will at least halve the number of consumer lookups we're executing.
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@candlepin-pull-request-bot retest this please |
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Updating the status of a large number of consumers (roughly 10000) could run the JVM out of memory due to all the consumers referenced in the consumerStackedEnts map. During status calculation, the consumer facts are accessed and during those accesses, the Hibernate proxy object is replaced by the actual map of facts. The consumerStackedEnts map would accordingly grow as each status was calculated. This patch detaches several model objects as soon as we stop needing them and most importantly, it detaches all the consumers in the consumerStackedEnts map. The consumers are then fetched again, receive an updated status, and are then immediately detached to keep the persistence context at roughly a constant size.
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- Added a new method, getConsumers(Collection), to ConsumerCurator for performing bulk consumer fetching/lookup - Updated the consumer status recalculation loop in CPM.deletePools to use the bulk consumer lookup
Updating the status of a large number of consumers (roughly 10000) could
run the JVM out of memory due to all the consumers referenced in the
consumerStackedEnts map. During status calculation, the consumer
facts are accessed and during those accesses, the Hibernate proxy object
is replaced by the actual map of facts. The consumerStackedEnts map
would accordingly grow as each status was calculated.
This patch detaches several model objects as soon as we stop needing
them and most importantly, it detaches all the consumers in the
consumerStackedEnts map. The consumers are then fetched again, the
status is updated, and then immediately detached to keep the persistence
context at roughly a constant size.