How to increase YSQL timeout in YugabyteDB - yugabytedb

Question

[Question posted by a user on YugabyteDB Community Slack]
Running 2.7.1.1 with 3 masters and 5 tservers.
Documentation shows ysql_client_read_write_timeout_ms overrides the client_read_write_timeout_ms gflag. Default for ysql_client_read_write_timeout_ms=-1 but can't find what -1 means? Dont override value I am guessing. The client_read_write_timeout_ms=60000.
Anyways, tserver are showing timeout at 60s despite if I change ysql_client_read_write_timeout_ms=300000 and restart tservers.
A simple test:
ysqlsh -h x -Ux -d x -c"select count(*) from x.table;"
ERROR: Timed out: [Timed out (yb/rpc/outbound_call.cc:512): Read RPC (request call id 158) to x:9100 timed out after 59.996s, Timed out (yb/rpc/outbound_call.cc:512): Read RPC (request call id 160) to x:9100 timed out after 59.996s, Timed out (yb/rpc/outbound_call.cc:512): Read RPC (request call id 164) to x:9100 timed out after 59.996s, Timed out (yb/rpc/outbound_call.cc:512): Read RPC (request call id 165) to x:9100 timed out after 59.996s, Timed out (yb/rpc/outbound_call.cc:512): Read RPC (request call id 166) to x:9100 timed out after 59.996s]
Tested values on all tservers and masters using curl to verify:
curl -s http://x:9000/varz | grep client_read_write_timeout_ms
--client_read_write_timeout_ms=60000
--ysql_client_read_write_timeout_ms=300000

Answer 1

Looking at the code in C++:
const auto default_client_timeout_ms =
(FLAGS_ysql_client_read_write_timeout_ms < 0
? std::max(FLAGS_client_read_write_timeout_ms, 600000)
: FLAGS_ysql_client_read_write_timeout_ms);
It means max of --client_read_write_timeout_ms and 600000ms. And, it looks like that code-path is only called when statement_timeout session variable is assigned. The common path is BuildSession, using pg_yb_session_timeout_ms flag. Setting --pg_yb_session_timeout_ms=300000 in yb-tservers and restarting them should make it work.