feat: add router_rebuild_min_interval to reduce CPU spikes from frequent route changes#13072
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membphis wants to merge 1 commit intoapache:masterfrom
Closed
feat: add router_rebuild_min_interval to reduce CPU spikes from frequent route changes#13072membphis wants to merge 1 commit intoapache:masterfrom
membphis wants to merge 1 commit intoapache:masterfrom
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…ent route changes When routes change frequently (e.g., 20-50 changes/sec), the HTTP router is rebuilt on every change which causes CPU spikes due to full radixtree recompilation with all routes. This adds a configurable minimum interval between HTTP router rebuilds. When set to a positive value (e.g., 1 or 5 seconds), rebuilds are throttled so the router is not recompiled more frequently than the configured interval, significantly reducing CPU usage during bulk route updates. Default value is 0 (rebuild immediately on every change), preserving backward compatibility.
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Description
When routes change frequently (e.g., 20-50 changes/sec with 5000+ total routes), the data plane rebuilds the radixtree router on every single change, causing significant CPU spikes (up to 80%) and temporary TPS drops.
This PR adds a configurable
router_rebuild_min_intervaloption that sets a minimum time interval (in seconds) between HTTP router rebuilds. When the interval has not elapsed since the last rebuild, subsequent route changes are acknowledged but the router rebuild is deferred, dramatically reducing CPU usage during bulk route updates.Configuration
Expected Impact
Changes
conf/config.yaml.example: Addedrouter_rebuild_min_intervalconfig optionapisix/cli/config.lua: Default value0apisix/router.lua: Reads config and passes to HTTP router modules (+3 lines)apisix/http/router/radixtree_uri.lua: Min interval check before rebuildapisix/http/router/radixtree_host_uri.lua: Min interval check before rebuildapisix/http/router/radixtree_uri_with_parameter.lua: Min interval check before rebuildt/router/router-rebuild-min-interval.t: Test cases covering default behavior, skip behavior, and deferred rebuildBackward Compatibility
Default value is
0, preserving the existing behavior of rebuilding immediately on every route change. No existing configurations are affected.