Only check latencies once every 10 seconds with routeByLatency
#2795
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`routeByLatency` currently checks latencies any time a server returns a MOVED or READONLY reply. When a shard is down, the ClusterClient chooses to issue the request to a random server, which returns a MOVED reply. This causes a state refresh and a latency update on all servers. This can lead to significant ping load to clusters with a large number of clients. This introduces logic to ping only once every 10 seconds, only performing a latency update on a node during the `GC` function if the latency was set later than 10 seconds ago. Fixes redis#2782
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LGTM! |
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Sure I'll push that change shortly. |
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@ofekshenawa PTAL when you get a chance! |
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routeByLatencycurrently checks latencies any time a server returns a MOVED or READONLY reply. When a shard is down, the ClusterClient chooses to issue the request to a random server, which returns a MOVED reply. This causes a state refresh and a latency update on all servers. This can lead to significant ping load to clusters with a large number of clients.This introduces logic to ping only once every 10 seconds, only performing a latency update on a node during the
GCfunction if the latency was set later than 10 seconds ago.Fixes #2782
Figure: Ping behavior of the client running 21bd40a and a client running this PR. When shards are failed the current cluster client will spam pings while the fixed cluster client will only ping each server once every 10 seconds.