Hi! IIUC one of limitations might be caused by mtr reserving 20 TCP ports per instance, first reserved port is 16000. This leaves (65535 - 16000) / 20= 2476.75 max possible mysqld instances.
Regards, Sergey On Sun, Feb 07, 2016 at 12:52:01PM +0100, Vladislav Vaintroub wrote: > > > On 2/6/2016 1:02 PM, Vicențiu Ciorbaru wrote: > >Hi Vlad, > > > >I'm looking at the community pull request > >https://github.com/grooverdan/mariadb-server/commit/a9dfee63bad7393002621f92c15f1debd535ee1a > > > >I have a question regarding your commit: > >2943d2b7e99b4221ef481890fc9a56ad569f3985 > > > >The contribution aims to remove the hard limit of 50 unique ids as it > >seems to cause problems for some use cases with a lot of proceeses. It > >does this by either leaving it at 50 or to be equal to the number of > >spawned processes. > > > >I'm thinking that even setting the limit of unique ids to num_processes > >might cause problems if there is another mtr running in parallel and both > >have > 50 processes. This is probably minor but why set this limit so low? > >Wouldn't a larger number (say 10k) be ok? Or why not generate a random > >number and lock a file with that number? (if the random number is invalid, > >generate a new one. On average it should finish quite quickly) > Hi Vicentiu, > The 50 ports range limit was there before my patch, I just moved the start > of the the range up from 250 to 300, so that the old mtr and "new"(i.e new > in 2008) mtr have non-overlapping port range- because these 2 mtrs have > different conflicting ideas of when a port is free. > > 10K or so limit should be fine. The reason why the limit is so small is > unknown to me. Perhaps back in the day 50 mysqlds on the same machine were > considered ought to be enough for anybody:) > > I'm not sure randomization needs implementing, unless a measurement would > show that it takes noticeable amount of time during startup. Randomization > could be a minor annoyance to some people if they are used to have > particular port numbers when mysqld is started via mtr, so if it does not > bring much , maybe better not to do it. > > > _______________________________________________ > Mailing list: https://launchpad.net/~maria-developers > Post to : [email protected] > Unsubscribe : https://launchpad.net/~maria-developers > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
