# git-svn very slow on fetch (shared git-svn repo) 5 messages from 2009-10-10 to 2009-10-11. Participants: Pascal Obry, Eric Wong. Thread: https://gitlist.dev/t/21182 ## Pascal Obry, 2009-10-10 09:10 Subject: git-svn very slow on fetch (shared git-svn repo) Message-ID: <4AD04F95.7050603@obry.net> URL: https://gitlist.dev/e/4AD04F95.7050603%40obry.net ``` Here is the problem. Doing a: $ git svn fetch Takes age to update the repository. The long story is that I'm trying to have shared git-svn repositories. I'm cloning the repository on a server using a standard "git svn clone". I then let users cloning this repository using the procedure described in git-svn help. Copy/paste here: << # Do the initial import on a server ssh server "cd /pub && git svn clone http://svn.example.com/project # Clone locally - make sure the refs/remotes/ space matches the server mkdir project cd project git init git remote add origin server:/pub/project git config --add remote.origin.fetch '+refs/remotes/*:refs/remotes/*' git fetch # Create a local branch from one of the branches just fetched git checkout -b master FETCH_HEAD # Initialize 'git svn' locally (be sure to use the same URL and -T/-b/-t options as were used on server) git svn init http://svn.example.com/project # Pull the latest changes from Subversion git svn rebase >> If you do a "git svn fetch" (to get new branches) it takes age if you have imported branches that are not used since a long time. I've traced this down to the Perl fetch_all procedure. It seems that the fetch is looking at the older version in all branches and then read the remote repository starting from this revision. As some branches are unused since a very long it it re-read most of the history. In my example it start at rev 8200 whereas the last revision on trunk is 150000 (I put trace in git-svn Perl script). I have observed that this happen only the first time. This can be confirmed by the fact that if you break git-svn fetch process and restart it it will start to a later revision. So it seems that git-svn is keeping some kind of data about what has already been fetched but those data are not properly copied by the procedure above. Is there a workaround that? Where are those data stored? Any guidance would be very welcomed. Thanks, Pascal. -- --|------------------------------------------------------ --| Pascal Obry Team-Ada Member --| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE --|------------------------------------------------------ --| http://www.obry.net - http://v2p.fr.eu.org --| "The best way to travel is by means of imagination" --| --| gpg --keyserver keys.gnupg.net --recv-key F949BD3B ``` ## Eric Wong, 2009-10-11 07:01 Subject: Re: git-svn very slow on fetch (shared git-svn repo) Message-ID: <20091011070136.GB16264@dcvr.yhbt.net> URL: https://gitlist.dev/e/20091011070136.GB16264%40dcvr.yhbt.net In-Reply-To: <4AD04F95.7050603@obry.net> ``` Pascal Obry wrote: > Here is the problem. > > Doing a: > > $ git svn fetch > > Takes age to update the repository. The long story is that I'm trying to > have shared git-svn repositories. > > I'm cloning the repository on a server using a standard "git svn clone". > I then let users cloning this repository using the procedure described > in git-svn help. Copy/paste here: > > << > # Do the initial import on a server > ssh server "cd /pub && git svn clone > http://svn.example.com/project > # Clone locally - make sure the refs/remotes/ space matches the > server > mkdir project > cd project > git init > git remote add origin server:/pub/project > git config --add remote.origin.fetch > '+refs/remotes/*:refs/remotes/*' > git fetch > # Create a local branch from one of the branches just fetched > git checkout -b master FETCH_HEAD > # Initialize 'git svn' locally (be sure to use the same URL and > -T/-b/-t options as were used on server) > git svn init http://svn.example.com/project > # Pull the latest changes from Subversion > git svn rebase > >> > > If you do a "git svn fetch" (to get new branches) it takes age if you > have imported branches that are not used since a long time. > > I've traced this down to the Perl fetch_all procedure. It seems that the > fetch is looking at the older version in all branches and then read the > remote repository starting from this revision. As some branches are > unused since a very long it it re-read most of the history. In my > example it start at rev 8200 whereas the last revision on trunk is > 150000 (I put trace in git-svn Perl script). > > I have observed that this happen only the first time. > > This can be confirmed by the fact that if you break git-svn fetch > process and restart it it will start to a later revision. So it seems > that git-svn is keeping some kind of data about what has already been > fetched but those data are not properly copied by the procedure above. > > Is there a workaround that? Where are those data stored? Hi Pascal, For globs (branches and tags) the $GIT_DIR/svn/.metadata config file, under the svn-remote.svn.{branches,tags}-maxRev keys. For explicitly specified refs (e.g. "trunk"), then it's in the last record of the corresponding rev_map (e.g. $GIT_DIR/svn/trunk/.rev_map.$UUID) as a 4-byte revision number + 20 bytes of zeroes. -- Eric Wong ``` ## Pascal Obry, 2009-10-11 09:00 Subject: Re: git-svn very slow on fetch (shared git-svn repo) Message-ID: <4AD19E9F.8010302@obry.net> URL: https://gitlist.dev/e/4AD19E9F.8010302%40obry.net In-Reply-To: <20091011070136.GB16264@dcvr.yhbt.net> ``` Hi Eric, > For globs (branches and tags) the $GIT_DIR/svn/.metadata > config file, under the svn-remote.svn.{branches,tags}-maxRev keys. Right. I found out that copying the .metadata solve this problem. > For explicitly specified refs (e.g. "trunk"), then it's in the last > record of the corresponding rev_map (e.g. > $GIT_DIR/svn/trunk/.rev_map.$UUID) as a 4-byte revision number + 20 > bytes of zeroes. Seems like we do not need to copy this one as it is reconstructed by a simple rebase on the trunk branch. This is quite fast as reconstructed from the embedded git-svn-id if I'm not mistaken. So you confirm that copying the .metadata is the solution? Pascal. -- --|------------------------------------------------------ --| Pascal Obry Team-Ada Member --| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE --|------------------------------------------------------ --| http://www.obry.net - http://v2p.fr.eu.org --| "The best way to travel is by means of imagination" --| --| gpg --keyserver keys.gnupg.net --recv-key F949BD3B ``` ## Eric Wong, 2009-10-11 09:03 Subject: Re: git-svn very slow on fetch (shared git-svn repo) Message-ID: <20091011090338.GA27480@dcvr.yhbt.net> URL: https://gitlist.dev/e/20091011090338.GA27480%40dcvr.yhbt.net In-Reply-To: <4AD19E9F.8010302@obry.net> ``` Pascal Obry wrote: > Hi Eric, > >> For globs (branches and tags) the $GIT_DIR/svn/.metadata >> config file, under the svn-remote.svn.{branches,tags}-maxRev keys. > > Right. I found out that copying the .metadata solve this problem. > >> For explicitly specified refs (e.g. "trunk"), then it's in the last >> record of the corresponding rev_map (e.g. >> $GIT_DIR/svn/trunk/.rev_map.$UUID) as a 4-byte revision number + 20 >> bytes of zeroes. > > Seems like we do not need to copy this one as it is reconstructed by a > simple rebase on the trunk branch. This is quite fast as reconstructed > from the embedded git-svn-id if I'm not mistaken. > > So you confirm that copying the .metadata is the solution? Yes, copying .metadata should be enough. The .rev_map rebuild should be fast. -- Eric Wong ``` ## Pascal Obry, 2009-10-11 09:37 Subject: Re: git-svn very slow on fetch (shared git-svn repo) Message-ID: <4AD1A760.9060006@obry.net> URL: https://gitlist.dev/e/4AD1A760.9060006%40obry.net In-Reply-To: <20091011090338.GA27480@dcvr.yhbt.net> ``` Eric, > Yes, copying .metadata should be enough. I've put this in place. Works fine. > The .rev_map rebuild should be fast. Yep. Thanks for your quick reply. Pascal. -- --|------------------------------------------------------ --| Pascal Obry Team-Ada Member --| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE --|------------------------------------------------------ --| http://www.obry.net - http://v2p.fr.eu.org --| "The best way to travel is by means of imagination" --| --| gpg --keyserver keys.gnupg.net --recv-key F949BD3B ```