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Optimize JacksonPersister#hydrateFromBytes #6750
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Optimize to avoid allocation of heap ByteBuffer via InputStreamReader. Remove after upgrade to Jackson 2.16. see: FasterXML/jackson-core#1081 and FasterXML/jackson-benchmarks#9
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👍 Fair enough, this is faithful to the change made in https://github.com/FasterXML/jackson-core/pull/1081/files. Thanks!
Released 0.937.0 |
After Jackson 2.16 is released and we bump, I'll put up a PR to remove the couple places we worked around this. |
Now that AtlasDB has upgraded to Jackson 2.16.1, remove performance workaround that landed upstream in Jackson 2.16.0. See FasterXML/jackson-core#1081 Removes changes from #6750
General
Before this PR:
Similar to #6739 , in AtlasDB heavy services deserializing values persisted as JSON via
JacksonPersister
can allocate significant (~135GB/s) java.nio.HeapByteBuffer. See FasterXML/jackson-core#1081 and FasterXML/jackson-benchmarks#9 for more details as we've improved this upstream in Jackson 2.16; however, we should mitigate these allocations until we 2.16 is released and we upgrade.After this PR:
==COMMIT_MSG==
Optimize to avoid allocation of heap ByteBuffer via InputStreamReader. Remove after upgrade to Jackson 2.16.
see: FasterXML/jackson-core#1081 and FasterXML/jackson-benchmarks#9
==COMMIT_MSG==
Priority:
Concerns / possible downsides (what feedback would you like?):
Is documentation needed?:
Compatibility
Does this PR create any API breaks (e.g. at the Java or HTTP layers) - if so, do we have compatibility?:
Does this PR change the persisted format of any data - if so, do we have forward and backward compatibility?:
The code in this PR may be part of a blue-green deploy. Can upgrades from previous versions safely coexist? (Consider restarts of blue or green nodes.):
Does this PR rely on statements being true about other products at a deployment - if so, do we have correct product dependencies on these products (or other ways of verifying that these statements are true)?:
Does this PR need a schema migration?
Testing and Correctness
What, if any, assumptions are made about the current state of the world? If they change over time, how will we find out?:
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If this PR contains complex concurrent or asynchronous code, is it correct? The onus is on the PR writer to demonstrate this.:
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Execution
How would I tell this PR works in production? (Metrics, logs, etc.):
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Will this change significantly affect our spending on metrics or logs?:
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If the above plan is more complex than “recall and rollback”, please tag the support PoC here (if it is the end of the week, tag both the current and next PoC):
Scale
Would this PR be expected to pose a risk at scale? Think of the shopping product at our largest stack.:
Would this PR be expected to perform a large number of database calls, and/or expensive database calls (e.g., row range scans, concurrent CAS)?:
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Development Process
Where should we start reviewing?:
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Please tag any other people who should be aware of this PR:
@jeremyk-91
@sverma30
@raiju