public-offering
/
pad.pub0.org
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix crash when client submits changeset based on too-old revision 

We had a problem with the server running out of stack space if a client
submitted a changeset based on a revision more than about 1000 revs old.
(944 was our cutoff but yours may vary). This happened in the wild with
about 30 people editing via flaky wifi. A disconnected client would try
to submit a fairly old changeset when reconnecting, and a few minutes
was enough for 30 people to generate that many revs.

The stack kept growing because pad.getRevisionChangeset was being answered
from the cache, so no I/O interrupted the callback chain. (This was seen with
mysql, I don't know about other backends.)

This patch forces a nextTick every 200 revisions to solve this problem.
pull/1025/head
Richard Braakman 2012-09-26 03:01:24 +03:00
parent e16008b371
commit f1b4206cad
1 changed files with 5 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/node/handler/PadMessageHandler.js
View File

@ -526,7 +526,11 @@ function handleUserChanges(client, message)
if(ERR(err, callback)) return; if(ERR(err, callback)) return;
changeset = Changeset.follow(c, changeset, false, apool); changeset = Changeset.follow(c, changeset, false, apool);
callback(null); if ((r - baseRev) % 200 == 0) { // don't let the stack get too deep
async.nextTick(callback);
} else {
callback(null);
}
}); });
}, },
//use the callback of the series function //use the callback of the series function