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### What problem does this PR solve? Issue Number: None Related PR: apache#67636 Problem Summary: CloudReplica image deserialization created independent String cluster IDs and boxed Long backend IDs for equivalent routes. The tested production image contains 4,197,906 replicas and 62,708,955 routes but only 15 cluster IDs and about 85 backend IDs, so millions of equal route identifiers retained duplicate heap objects. Canonical sharing reduced forced-GC live heap from 15,311,045,744 bytes to 8,539,550,968 bytes, saving 6,771,494,776 bytes (6.31 GiB, 44.2%). Intern cluster IDs and primary backend IDs on route updates and after image deserialization so equal routes reuse the same objects. Use Guava weak interners instead of strong process-lifetime maps: active routes keep canonical objects alive, while identifiers become collectable after their last route is removed. Routing behavior and the serialized image format are unchanged. The full 6.93 GB image completed compatibility load and dump with the final weak-interner implementation. A clean run loaded in 225.679 seconds and dumped in 145.935 seconds. JFR attributed 255 of 18,139 load-stage CPU samples (1.41%) to the interner path, with no sampled allocations attributed directly to it. ### Release note Reduce FE heap usage for CloudReplica routing metadata and release unused historical route identifiers. ### Check List (For Author) - Test: Unit Test / Manual test - CloudReplicaTest: 23 tests passed - ./build.sh --fe passed with Checkstyle 0 violations - Full production image compatibility load and dump passed - JFR profile verified the interner path is not a load hotspot - Behavior changed: Yes; equal in-memory route identifiers are shared and unused canonical identifiers can be reclaimed, without changing routing results or image serialization - Does this need documentation: No
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run buildall |
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/review |
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Complete static review of PR #68783 at b26ee79. I found no substantiated new inline issues and no still-applicable existing P0/P1 comments. Both changed files and their related route, image, replay, and cleanup paths were reviewed. No additional user focus points were supplied.
Critical checkpoints:
- Goal, scope, and tests: Weak interning shares equal primary cluster/backend identifiers on updates and image load, and shares secondary cluster identifiers on live updates. The change is confined to CloudReplica and focused unit tests. The inspected tests check identity on updates, current and legacy image formats, JSON equality, and collection after route removal. They were not run in this review.
- Concurrency and locks: Query routing, rebalancing, and catalog replay can update routes concurrently through ConcurrentHashMap. The shared interners are concurrency-safe and map operations use value equality. Image post-processing completes in Gson's read adapter before the replica is returned to callers, so replacing its map does not race with published route updates. No new explicit locks, lock ordering, blocking I/O, or heavy work under a catalog lock were found.
- Lifecycle: Live map entries strongly retain their canonical keys and values; the weak interners allow unused identifiers to be collected after route removal. Static initialization has no cross-unit dependency or ownership cycle. Secondary routes are omitted from ordinary images by Doris's annotation-based serialization rule and are interned when recreated at runtime.
- Configuration and compatibility: No config, function symbol, FE/BE field, or persisted format changed. Current
beand legacybesmaps both reach the new canonicalization after legacy migration and stale-route cleanup. Journal replay uses the same primary update method; no new failover or transaction persistence gap was found. - Parallel paths and conditions: Primary assignments from query fallback, rebalancer, warmup, and replay use the updated method; secondary fallback and smooth upgrade use the updated secondary method. Existing route cleanup and value-based lookup semantics remain intact. The new condition-free interner helpers do not introduce a special-case behavior change.
- Coverage and results: Existing tests cover stale-route cleanup and fallback behavior; new tests cover the changed object-sharing paths. No regression result file changed. The PR description reports FE unit/build and production-image checks, but this review did not independently execute builds, tests, or the image load, as required by the review instructions.
- Observability, data writes, and performance: No data write or visibility path changed, and existing route logs remain applicable; new metrics or logs are not needed for object sharing. Image load creates one transient replacement map per replica and route writes add interner lookups, but the inspection found no concrete material regression. The stated heap and JFR measurements are author-provided, not independently reproduced here.
One candidate about secondary routes surviving image reload was withdrawn after confirming the secondary map is excluded from normal image serialization. All three independent review passes returned NO_NEW_VALUABLE_FINDINGS after that correction, and the final changed-file sweep left no unresolved points. Review complete.
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TPC-H: Total hot run time: 29085 ms |
gavinchou
reviewed
Oct 8, 2026
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gavinchou
approved these changes
Oct 8, 2026
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TPC-DS: Total hot run time: 152458 ms |
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ClickBench: Total hot run time: 24.61 s |
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FE Regression Coverage ReportIncrement line coverage |
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FE UT Coverage ReportIncrement line coverage |
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What problem does this PR solve?
Issue Number: None
Related PR: #67636
Problem Summary: CloudReplica image deserialization created independent String cluster IDs and boxed Long backend IDs for equivalent routes. The tested production image contains 4,197,906 replicas and 62,708,955 routes but only 15 cluster IDs and about 85 backend IDs, so millions of equal route identifiers retained duplicate heap objects. Canonical sharing reduced forced-GC live heap from 15,311,045,744 bytes to 8,539,550,968 bytes, saving 6,771,494,776 bytes (6.31 GiB, 44.2%).
Intern cluster IDs and primary backend IDs on route updates and after image deserialization so equal routes reuse the same objects. Use Guava weak interners instead of strong process-lifetime maps: active routes keep canonical objects alive, while identifiers become collectable after their last route is removed. Routing behavior and the serialized image format are unchanged.
The full 6.93 GB image completed compatibility load and dump with the final weak-interner implementation. A clean run loaded in 225.679 seconds and dumped in 145.935 seconds. JFR attributed 255 of 18,139 load-stage CPU samples (1.41%) to the interner path, with no sampled allocations attributed directly to it.
Release note
Reduce FE heap usage for CloudReplica routing metadata and release unused historical route identifiers.
Check List (For Author)
What problem does this PR solve?
Issue Number: close #xxx
Related PR: #xxx
Problem Summary:
Release note
None
Check List (For Author)
Test
Behavior changed:
Does this need documentation?
Check List (For Reviewer who merge this PR)