perf: Avoid heap allocation in cluster_dist_write node list#2857
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cluster_dist_write emalloc'd a small int array (master + slaves) on every read command issued under a failover-distribution mode, then freed it. A shard's replica count is small in practice, so build the index list on a 16-element stack array and only fall back to emalloc for larger fan-outs. Both free sites are now guarded against freeing the stack.
michael-grunder
approved these changes
Jun 2, 2026
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cluster_dist_writeemalloc'd a small int array (master + slaves) on every read issued under a failover-distribution mode, then freed it. A shard's replica count is small in practice.Build the index list on a 16-element stack array and fall back to
emalloconly for larger fan-outs. Both free sites are guarded against freeing the stack.Compile-verified against PHP 8.4 (no cluster available for a runtime test).