Strategy for fts and Replication

[Philon]

Hi Francis,

My Solr instance is on 1GB but using less than 512MB. You might need to 
adjust Java VM memory usage but it's possible. I have only my own email 
but also 10-15 years history and search results including headers and 
body are instant.

Things are on SSD but still I think the search storage fits into memory.


Philon

Am 04.02.2020 11:46, schrieb Francis Augusto Medeiros-Logeay:
> Hi Philon,
> 
> Thanks a lot for your thoughts!
> 
> Can I ask you if using Solr improved things for you? I have a mailbox
> with 15 years of e-mail and searching things take a long time.
> 
> On 04.02.2020 09:39, Philon wrote:
>> Hi Francis,
>> 
>> next to fts-solr there was fts-lucene. But that Lucene there seems
>> heavily outdated why the Dovecot docs also suggest using Solr.
>> Elasticsearch probably is similar to Solr but the later is maintained
>> by Dovecot team.
>> 
>> I started with downloading the Solr binary distribution to Debian with
>> JRE preinstalled and things were running like after 10 min. Yes it’s a
>> bit more complicated to find the schema and edit things like header
>> size (in tips section). It’s running quite nicely since then and has
>> zero maintenance.
> 
> I will try again - I kept getting some weird errors, so I don't know
> if that's why I wasn't seing much of improvement.
> 
>> 
>> As FTS indexes are separate in external Solr instance I’d guess that
>> it won’t interfere with dsync. What I don’t know is if dsync’ing would
>> trigger indexing. This brings me to wonder how one could actually
>> replicate the Solr instance!?
> 
> Good question. But what I thought about doing was to install FTS on my
> backup instance, and if things go fine, then I install an FTS instance
> on my production server - that is, if one doesn't interfere with the
> other.
> 
> I will give Solr another shot - my worries are mostly if Solr is
> supported on ARM (my prod instance is running on ARM) - I know
> Elasticsearch has an ARM build.
> 
> Ii thought about the Xapian engine, but since it requires dovecot 2.3,
> I will have to wait.
> 
> Best,
> 
> Francis
> 
> 
>> 
>> Philon
>> 
>>> On 31 Jan 2020, at 17:24, Francis Augusto Medeiros-Logeay 
>>> <r_f at med-lo.eu> wrote:
>>> 
>>> Hi there,
>>> 
>>> I got successfully to replicate my mail server to another dovecot 
>>> install using dsync, mainly for redundancy, and it works great.
>>> 
>>> I want to try to install fts, as some of the mailboxes have tens of 
>>> thousands of messages, and it takes minutes to get some results when 
>>> searching via IMAP on a Roundcube interface.
>>> 
>>> I want to experiment with fts-solr first, and firstly on my redundant 
>>> server, ie., not on my main dovecot install. Is it ok to do this? I 
>>> ask because I am afraid of how this whole reindexing on the redundant 
>>> install will affect the production server.
>>> 
>>> Also, any tips on something else than fts-solr? I tried it once, but 
>>> it was so hard to get it right, so many configurations, java, etc., 
>>> that I'd rather try something else. I also could try fts-elastic or 
>>> something like that, but, again, having to maintain an elasticsearch 
>>> install might use more resources than I think is worth. Any thoughts 
>>> on that?
>>> 
>>> Best,
>>> 
>>> --
>>> Francis
>>>