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<div dir="ltr"><div dir="ltr">Hi </div><div dir="ltr">can anyone suggeset why i get backend connection failed when N-Worker_thread goes </div><div dir="ltr">anything above default of 100 worker_thread?</div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">While trying to create 491 thread in peak it was unable to connect to backend.</div><div dir="ltr">whereas, backend servers were not in load or anything.</div><div dir="ltr"><br></div><div dir="ltr">As i understood, while thread max is 1000 * 2[pools], and varnish server load is below 1, theoritically it should be able to handle that many spikes, And i would not see why backend would fail here.</div><div dir="ltr"><br></div><div dir="ltr">Also, Due to demand of use, it is designed to cache 1s to 5s at most.</div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">n_worker_thread = 100 , all good</div><div dir="ltr">n_worker_thread = 491 , 8 backend_connection failure.</div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">varnishadm</div><div dir="ltr"><br></div><div dir="ltr">thread_pool_add_delay 2 [milliseconds]</div><div dir="ltr">thread_pool_add_threshold 2 [requests]</div><div dir="ltr">thread_pool_fail_delay 200 [milliseconds]</div><div dir="ltr">thread_pool_max 1000 [threads]</div><div dir="ltr">thread_pool_min 50 [threads]</div><div dir="ltr">thread_pool_purge_delay 1000 [milliseconds]</div><div dir="ltr">thread_pool_stack unlimited [bytes]</div><div dir="ltr">thread_pool_timeout 120 [seconds]</div><div dir="ltr">thread_pool_workspace 65536 [bytes]</div><div dir="ltr">thread_pools 2 [pools]</div><div dir="ltr">thread_stats_rate 10 [requests]</div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">varnishstat</div><div dir="ltr">32+03:45:05</div><div dir="ltr">Hitrate ratio: 2 2 2</div><div dir="ltr">Hitrate avg: 0.9404 0.9404 0.9404</div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">backend_conn 4516262 1.63 Backend conn. success</div><div dir="ltr">backend_unhealthy 0 0.00 Backend conn. not attempted</div><div dir="ltr">backend_busy 0 0.00 Backend conn. too many</div><div dir="ltr">backend_fail 9562 0.00 Backend conn. failures</div><div dir="ltr">backend_reuse 67350518 24.24 Backend conn. reuses</div><div dir="ltr">backend_toolate 361647 0.13 Backend conn. was closed</div><div dir="ltr">backend_recycle 67715544 24.38 Backend conn. recycles</div><div dir="ltr">backend_retry 5133 0.00 Backend conn. retry</div><div dir="ltr">n_backend 5 . N backends</div><div dir="ltr">backend_req 71855086 25.87 Backend requests made</div><div dir="ltr">LCK.backend.creat 5 0.00 Created locks</div><div dir="ltr">LCK.backend.destroy 0 0.00 Destroyed locks</div><div dir="ltr">LCK.backend.locks 149007648 53.64 Lock Operations</div><div dir="ltr">LCK.backend.colls 0 0.00 Collisions</div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">Regards</div><div dir="ltr">Tikejhya</div></div>
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