Large commit cause application error in Gerrit Web UI

[Bailey, Darragh]

Hi,

Looks like we've run into issue
http://code.google.com/p/gerrit/issues/detail?id=1068

I could still fetch the change via the command line and, after running
'git format-patch' against it, I see that the resulting diff is 76MB in
size. No binaries involved, so I'm guessing just the raw size and number
of diffs causes the problem.

Using 'git log -1 --shortstat' on the problem commit shows the following
summary of changes:
188 files changed, 302387 insertions(+), 414 deletions(-)

Given I can still use the command line tools to query for general
information on the change, it seems that the main problem is in the Web
UI or rather when Gerrit needs to look at the actual changes, since it
also blew up when asking for the list of files affected on the command line.


Trying to access the review in the web UI resulted in the following
error appearing in the logs:

ERROR com.google.gerrit.ehcache.PopulatingCache : Cannot lookup
PatchListKey[<project-name>
BASE..1c83a0f2b1ef042511ad6c0f5188f4a24b337a03 IGNORE_NONE] in "diff"
net.sf.ehcache.CacheException: Could not fetch object for cache entry
with key "PatchListKey[<project-name>
BASE..1c83a0f2b1ef042511ad6c0f5188f4a24b337a03 IGNORE_NONE]".

Followed by a stack trace ending with:
Caused by: java.lang.StackOverflowError
at
org.eclipse.jgit.diff.HistogramDiffIndex.scanA(HistogramDiffIndex.java:195)
at
org.eclipse.jgit.diff.HistogramDiffIndex.findLongestCommonSequence(HistogramDiffIndex.java:171)
at
org.eclipse.jgit.diff.HistogramDiff$State.diffReplace(HistogramDiff.java:155)
at
org.eclipse.jgit.diff.HistogramDiff$State.diff(HistogramDiff.java:195)
at
org.eclipse.jgit.diff.HistogramDiff$State.diffReplace(HistogramDiff.java:167)
at
org.eclipse.jgit.diff.HistogramDiff$State.diff(HistogramDiff.java:195)

Last two lines are repeated ~500 times


Running version 2.4.2, so wondering if anyone would know if there have
been any changes in this area that improve things in the latest gerrit?

Alternatively, are there any settings that can help?


--
Regards,
Darragh Bailey

[Adam Pryce]

We are seeing this same issue in Gerrit 2.8.3. Our big change was:

34k lines

5.2 MB

A handful of files, one large and the rest normal.

Adam