228423 - When attachments table hits 4GB, attempts to add attachments get stuck

Status: RESOLVED FIXED

(Bugzilla :: Documentation, defect, P3)

Description

[Joel Peshkin]

Mysql returns a "table full" error which is not fielded by attchment.cgi very
gracefully if a new attachment pushes the table past the limit.

Mysql has a default table size limit of 4GB independent of the filesystem.  To
get past this, the table should be created with something like
AVG_ROW_LENGTH=1000000 and MAX_ROWS=100000

Some portion of Bugzilla (checksetup??) should do something more clever than it
does.

Comment 1

[Bradley Baetz (:bbaetz)]

Get a better database :)

I don't think we want this (except in docs). Presumably theres a penalty of some
sort for most normal bugzilla users.

Comment 2

[Joel Peshkin]

So there are 3 things we might decide to do with this.

1) Improve the way attachment.cgi handles the "table is full" error so it throws
a meningful message instead of just sitting there looking hung.

2) Put a note in the documentation telling admins to execute ...
alter table attachments AVG_ROW_LENGTH=1000000, MAX_ROWS=20000;
to raise the limit to 20GB, for example.  The documentation should suggest this
be done early since it is really a pain to do this once the table has grown to
4GB.  The same section should probably mention the use of RAID_TYPE for folks
with 2GB limits or other reasons to prefer smaller files.

3) It may pay to devise a way of avoiding retaining obsolete attachments
forever.  Some sort of retention policy that permits an attachment to be
(optionally: archived and) removed if it does not have a flag indicating that it
should be kept forever, is either obsolete or attached to a reolved bug, has not
been viewed in a certain length of time, etc...
   Since these databases tend to fill up with core-dumps, traces, etc...  it
would be useful to be able to clean it up a bit.

Comment 3

[Joel Peshkin]

Well, the most important place is in the documentation.

Comment 4

[Dave Miller [:justdave]]

Jake is leaving for a while (Reserve unit got called up), and we don't have a
new docs owner yet.  Anyone interested in helping out, please add
[e-mail] to your watch list in your email preferences in Bugzilla.

Comment 5

[Joel Peshkin]

Attachment: Documentation patch

Comment 6

[Christian Reis]

Comment on attachment 143816 [details] [diff] [review]
Documentation patch

>Index: docs/xml/installation.xml
>+        <para>By default, mysql will limit the size of a table

For consistency with the rest of the docs, I suggest using MySQL when referring
to the database software.

>+        has no such limit or if you are using RAID.  

Is RAID relevant here? Normally RAID is implemented transparently to the
filesystem, so should it matter here if you've got an array going or not?

to 20GB. Mysql will have 

Again, MySQL 

to do this. Ideally, do 
>+        this when your attachments table is still small.</para>

I would change this to "Ideally, you should do this.."

r=kiko with those considerations

Comment 7

[Dave Miller [:justdave]]

a= justdave, assuming you fix kiko's nits in comment 6

Comment 8

[Joel Peshkin]

Nits covered.
Checked in.