When I run a query rule to fetch data from database, I got below error. It seems

Not sure of the error but the place for setting the timout parameter is
forum.appian.com/.../Post-Install_Configurations.html
But changing the default configurations is not advisable rather than changing the query itself to return the data in the specified time. Hope this would help !!!

@shaoyongw The error seems to be associated with the timeout in the query that's being made. Rather than modifying the timeout setting(Reference: conf.data.query.timeout at https://forum.appian.com/suite/help/7.11/Post-Install_Configurations.html#Query_Rule_Limits), I would like to suggest you to get the data in terms of batches. That is, make use of the startIndex and batchSize effectively, (for the first batch it should 1 - 5, for second batch it should be 6 - 10 and so on) and obtain the entire data in multiple hits.