On Thu, Oct 19, 2017 at 8:30 AM, Thomas Singer <thomas.sin...@syntevo.com> wrote: > On 18.10.2017 19:56, Branko Čibej wrote: >> >> On 18.10.2017 13:31, Thomas Singer wrote: >>> >>> Hi, >>> >>> When performing following steps on my old Linux test machine (with >>> slow hard disk): >>> >>> - have a SVN working copy at /home/user/test >>> - sudo apt install nfs-kernel-server >>> - add following line to /etc/exports: >>> /home/user/test *(rw,sync,no_root_squash) >>> - start the NFS server: >>> sudo systemctl start nfs-kernel-server.service >>> - mount the NFS share: >>> sudo mount localhost:/home/user/test /home/user/test.nfs >>> >>> and then open /home/user/test.nfs in SmartSVN 9.2 (using SVN 1.9 >>> JavaHL binaries), adding/removing a file is very slow. It boils down >>> to the call ISVNClient.getChangelists which takes ~8s on the NFS share >>> (/home/user/test.nfs). First, I thought, it would be caused by the >>> native-Java overhead calling the call-back ~11,000 times for my >>> working copy, but when using the working copy directly >>> (/home/user/test), the method just takes <1s though the ~11,000 times >>> call-back invocations are still there. >>> >>> My working copy has no local modifications, no untracked or ignored >>> files, no changelists. >>> >>> Is it expected that this method (ISVNClient.getChangelists) is so slow >>> on a NFS share even if there are no changelists? >> >> >> I don't know if it's "expected" but I bet that NFS is killing SQLite >> performance. >> >> >> https://www.mail-archive.com/sqlite-users@mailinglists.sqlite.org/msg88989.html >> >> I'm not sure about the reason but the most likely answer, apart from >> slow data rate and latency when compared to a local filesystem (which, >> in your case on loopback, should not be an issue), is that the OS can't >> really use a cache for files on NFS since it has no way to know whether >> or not it's valid. With a lot of random-access reads and writes, that >> can be a HUGE slowdown, as you found. >> >> >> Also this: >> https://sqlite.org/faq.html#q5 >> >> In other words, Subversion working copies on NFS are, and have always >> been, a bad idea; not only because of SQLite but also because >> Subversion's code itself relies on atomic renames, which NFS does not >> provide. >> >> -- Brane > > > What SVN command (on command line) I should test to get a similar result as > from ISVNClient.getChangelists? I've tried "git status" and it just needs > <1s on the NFS working copy.
I assume you meant "svn status", not "git status". I have no idea what ISVNClient.getChangelists corresponds to compared with the native 'svn' commandline. But one thing that might be relevant: in the client-side configuration file 'config' there are two properties that can have a big influence here: (see %APPDATA%/Subversion/config on Windows, or ~/.subversion/config on Unix) [[[ ### Section for configuring working copies. [working-copy] ### Set to a list of the names of specific clients that should use ### exclusive SQLite locking of working copies. This increases the ### performance of the client but prevents concurrent access by ### other clients. Third-party clients may also support this ### option. ### Possible values: ### svn (the command line client) # exclusive-locking-clients = ### Set to true to enable exclusive SQLite locking of working ### copies by all clients using the 1.8 APIs. Enabling this may ### cause some clients to fail to work properly. This does not have ### to be set for exclusive-locking-clients to work. # exclusive-locking = false ]]] So with the above options you can make all clients (that use that config file) respect "exclusive-locking" (with the exclusive-locking flag), or just a subset of specific client applications (with the exclusive-locking-clients property). Perhaps your commandline 'svn' invocation uses the standard ~/.subversion/config file, which has the exclusive-locking flag set, and your SmartSVN application might use another one (it can choose another "config dir"). -- Johan
