973871 - Network Seer thread periodically writes to disk during idle

Status: RESOLVED DUPLICATE of bug 1009122

(Core :: Networking, defect)

Description

[Roberto Agostino Vitillo (:rvitillo)]

The disk writes on a complete idle system are dominated by the ones performed periodically by the Network Seer thread (measured with iotop with 6 tabs open pointing to cnn.com). Are those writes necessary?

Comment 1

[Roberto Agostino Vitillo (:rvitillo)]

Those writes account for about 50% of the total periodic writes performed by FF in an one hour period (~60MB).

Comment 2

[Roberto Agostino Vitillo (:rvitillo)]

The file being written to is netpredictions.sqlite.

Comment 3

[Patrick McManus [:mcmanus]]

rvtillo - jduell is away this week. :hurley can certainly help you - but it isn't clear what info you are requesting. Is your data up to date - there have been a lot of seer changes since this was filed. (but again - nick is the person to follow up with)

Comment 4

[Roberto Agostino Vitillo (:rvitillo)]

It seems that the same behavior persists also with the latest changes. My question is what kind of event can cause a write to netpredictions.sqlite? Now, cnn.com is a particular case because the page reloads itself periodically but I still find surprising that the Network Seer threads performs more writes than any other thread.

Comment 5

[u408661]

It's probably the commit timer causing extraneous writes. That should be relatively easy to fix, if we want to pursue the patch. There are also (still relatively nascent) plans to rewrite the backend to not use sqlite, which would also fix the issue.

Comment 6

[Richard Newman [:rnewman]]

How about both? Let's fix the commit timer now, regardless of a future backend rewrite.

Comment 7

[u408661]

Rewrote to no longer have a seer thread, so this is now effectively a dupe of the rewrite bug.