Page 1 of 1

Profiling session to occur Sunday or Monday night

Posted: Sat Apr 23, 2016 8:46 am
by Steve Sokolowski
On Sunday or Monday night, Chris will be conducting a "profiling" session of the production mining server.

Months ago, we spent a significant amount of time improving the performance of the database. The changes have proven successful, and we estimate that the database can now handle the entire litecoin network's hashrate. However, CPU usage of the mining server was not significantly addressed at the time, and it may max out as early as 75 GH/s.

We've profiled the mining server on the development environment. While we can simulate a lot of users there, we don't have the resources to be able to use a lot of coins at once and to find blocks. The only way to figure out how much impact those two things have on performance, and which lines can provide the most significant improvements, is to enable a profiling mode that writes every function call to a file.

Because we've never done this before on production, we don't know if CPU usage will reach 100% under profiling mode, which would cause rejected shares. I expect that five minutes of this will be long enough to gather the data we need, and then we can improve performance offline. We'll need to do a restart, then five minutes of profiling, and then another restart to restore things to normal.

We apologize for the inconvenience. The impact to profits should be minimal, but you may be alerted through notification E-Mails that your rejected share amounts rose or that your hashrate dropped for a few minutes.

Re: Profiling session to occur Sunday or Monday night

Posted: Sat Apr 23, 2016 9:42 am
by kires
Thanks for the headsup, Steve. Just out of curiosity, why wait until the wee small hours to run the profiling? It makes intuitive sense to do stuff like this on overnights in order to ameliorate impact on the end-user, but is there a technical reason it's preferable for the mining server?

Re: Profiling session to occur Sunday or Monday night

Posted: Sat Apr 23, 2016 12:08 pm
by Chris Sokolowski
I don't think there is a technical reason for the time; it just aligns with my schedule. I sleep 6AM-1:30PM so that I can perform the daily server maintenance in the early mornings without affecting users. It's also opposite Steve's schedule so that we can respond to issues quickly and share resources like a single development server. Doing the profiling at that time isn't anything out of the ordinary for me; it's just normal work hours.

Re: Profiling session to occur Sunday or Monday night

Posted: Mon Apr 25, 2016 8:13 am
by Steve Sokolowski
This session has now ended. Thanks for your understanding!