Project: datamanagement
Issue DM-3448: S17 Long-running Query Optimizations
As discovered through DM-3432 when a query runs for long time, czar does not get response from worker for a long time, and times out. A quick patch we did during Summer 2015 tests was to increase the timeout to a large number. The issue was discussed at [Qserv mtg Aug 12 2015|https://confluence.lsstcorp.org/display/DM/Database+Meeting+2015-08-12]. If we knew how long a query was going to take, we could set the timeout to appropriate value, but we can't always estimate well how long the query is going to take. The best solution we came up with: periodically check with the worker asynchronously what the status of the query is. Worker should respond with something like: queued, scheduled, working / started x sec ago. Note, this might require changes to the xrdssi API.
Story points: 26