[Dovecot] Issues with VANISHED CHANGEDSINCE

[Timo Sirainen]

On 5.11.2012, at 20.37, Michael J Rubinsky wrote:

>> On 5.11.2012, at 18.13, Michael J Rubinsky wrote:
>> 
>>> I've been seeing the following wonky behavior with Dovecot. Currently this is with Dovecot 2.0.19, but I was also seeing it in earlier versions as well, including versions from the 1.x series.  Some background, this is from Horde's ActiveSync library, when it is trying to determine what UIDs have recently been expunged.  I can guarantee that when this command was sent, there was only one or two emails that were removed since the provided MODSEQ value.
>> ..
>>> <quote>
>>> There's definitely something wonky going on in the code.  There's a certain tipping point of modseqs where the values become incorrect.
>> 
>> I don't think they become incorrect, just that there are more of them than really necessary? Yes, there's a tipping point. It's when the modseq no longer exists in the dovecot.index.log* files, which get rotated once in a while. This shouldn't happen very often.
> 
> FYI, I see this about once every two weeks, sometimes more frequently. Is there anything we can do to reduce the chance of this happening?

How do you see it? Does it break something? Why?

You can change it only by increasing the dovecot.index.log sizes, which requires changing the code.