Hi Shawn / Jan, Do we have any further insights about this problem? The same problem still happens even after we make the changes and re-index all the data.
Regards, Edwin On Sun, 27 Jan 2019 at 07:48, Zheng Lin Edwin Yeo <edwinye...@gmail.com> wrote: > Hi Shawn, > > Thanks for your reply. Below are the replies to your email: > > 1) We have tried to set the heap size to be 8g previously when we faced > the same issue, and changing to 7g does not help too. > > 2) We are using standard disk at the moment. > > 3) In the link is the screenshot of the process list that is sort by > Commit. > > https://drive.google.com/file/d/1TzxaAqbDJwYO0aHo9GW34p2kncnylRkG/view?usp=sharing > > Regards, > Edwin > > On Sun, 27 Jan 2019 at 02:07, Shawn Heisey <apa...@elyograg.org> wrote: > >> On 1/26/2019 9:40 AM, Zheng Lin Edwin Yeo wrote: >> > We have tried to add -a "-XX:+AlwaysPreTouch" that starts Solr, but >> there >> > is no noticeable difference in the performance. >> > >> > As for the screenshot, I have captured another one after we added -a >> > "-XX:+AlwaysPreTouch", and it is sorted on the Working Set column. >> > Below is the link to the new screenshot: >> > >> https://drive.google.com/file/d/1YEsJxnCeRorvBRCSqeowZOu3Fpena5Mo/view?usp=sharing >> >> That would mean that it's probably not a heap issue. You could try >> increasing the heap size on each Solr instance to 7g as a test to see >> whether it helps at all. I'd be a little bit surprised if that helps. >> >> I can't tell much about the software other than Solr that's running on >> this machine, but my best guess at this point is that Solr index >> information is being pushed out of the disk cache by the other software >> running on the machine, making it so that when Solr needs to do a query, >> a lot of information must be read from disk instead of the cache. Disks >> are very very slow compared to memory. SSD is faster, but still quite a >> bit slower than main memory. >> >> What kind of disk are you using? If it's standard disks, I don't know >> how easily you could try putting the index data on SSD. If doing so >> makes it quite a bit faster, then my suspicion above is probably correct. >> >> A "by the way" question: What do you see if you sort the process list >> by Commit instead? Doing this might not reveal anything useful. Only >> software using MMAP for file access (which Solr does by default) would >> show up near the top of that list, so it's possible that a new sort >> would not reveal anything interesting. >> >> Thanks, >> Shawn >> >
