Hello, On Tue, Feb 7, 2017 at 5:14 PM, Mithun Cy <mithun...@enterprisedb.com> wrote:
> On Tue, Feb 7, 2017 at 12:24 PM, Amit Kapila <amit.kapil...@gmail.com> > wrote: > > On Tue, Feb 7, 2017 at 11:53 AM, Beena Emerson <memissemer...@gmail.com> > wrote: > >> Are 2 workers required? > >> > > > > I think in the new design there is a provision of launching the worker > > dynamically to dump the buffers, so there seems to be a need of > > separate workers for loading and dumping the buffers. However, there > > is no explanation in the patch or otherwise when and why this needs a > > pair of workers. Also, if the dump interval is greater than zero, > > then do we really need to separately register a dynamic worker? > > We have introduced a new value -1 for pg_prewarm.dump_interval this > means we will not dump at all, At this state, I thought auto > pg_prewarm process need not run at all, so I coded to exit the auto > pg_prewarm immediately. But If the user decides to start the auto > pg_prewarm to dump only without restarting the server, I have > introduced a launcher function "launch_pg_prewarm_dump" to restart the > auto pg_prewarm only to dump. Since now we can launch worker only to > dump, I thought we can redistribute the code between two workers, one > which only does prewarm (load only) and another dumps periodically. > This helped me to modularize and reuse the code. So once load worker > has finished its job, it registers a dump worker and then exists. > But if max_worker_processes is not enough to launch the "auto > pg_prewarm dump" bgworker > We throw an error > 2017-02-07 14:51:59.789 IST [50481] ERROR: registering dynamic > bgworker "auto pg_prewarm dump" failed c > 2017-02-07 14:51:59.789 IST [50481] HINT: Consider increasing > configuration parameter "max_worker_processes". > > Now thinking again instead of such error and then correcting same by > explicitly launching the auto pg_prewarm dump bgwroker through > launch_pg_prewarm_dump(), I can go back to original design where there > will be one worker which loads and then dumps periodically. And > launch_pg_prewarm_dump will relaunch dump only activity of that > worker. Does this sound good? > Yes it would be better to have only one pg_prewarm worker as the loader is idle for the entire server run time after the initial load activity of few secs. -- Thank you, Beena Emerson Have a Great Day!
