Re: FTS delays

It's because you're misunderstanding how the lookup() function works. It gets ALL the search parameters, including the "mailbox inbox". This is intentional, and not a bug. Two reasons being:

1. The FTS plugin in theory could support indexing/searching any kinds of searches, not just regular word searches. So I didn't want to limit it unnecessarily.

2. Especially with "mailbox inbox" this is important when searching from virtual mailboxes. If you configure "All mails in all folders" virtual mailbox, you can do a search in there that restricts which physical mailboxes are matched. In this case the FTS backend can optimize this lookup so it can filter only the physical mailboxes that have matches, leaving the others out. And it can do this in a single query if all the mailboxes are in the same FTS index.

So again: Your lookup() function needs to be changed to only use those search args that it really wants to search, and ignore the others. Use solr_add_definite_query_args() as the template.

Also I see now the reason for the timeout problem. It's because you're not setting search_arg->match_always=TRUE. These need to be set for the search args that you're actually using to generate the Xapian query. If it's not set, then Dovecot core doesn't think that the arg was part of the FTS search and it processes it itself. Meaning that it opens all the emails and does the search the slow way, practically making the FTS lookup ignored.

On 21 Apr 2019, at 19.50, Joan Moreau jom@grosjo.net wrote:

No, the parsing is made by dovecot core, that is nothing the backend can do about it. The backend shall *never* reveive this. (would it be buggy or no)

PLease, have a look deeper

And the loop is a very big problem as it times out all the time (and once again, this is not in any of the backend functions)

On 2019-04-21 10:42, Timo Sirainen via dovecot wrote:

...

Inbox appears in the list of arguments, because fts_backend_xapian_lookup() is parsing the search args wrong. Not sure about the other issue.

...

On 21 Apr 2019, at 19.31, Joan Moreau mailto:jom@grosjo.net> wrote:

For this first point, the problem is that dovecot core sends TWICE the request and "Inbox" appears in the list of arguments ! (inbox shall serve to select teh right mailbox, never sent to the backend)

And even if this would be solved, the dovecot core loops *after* the backend hs returneds the results

# doveadm search -u jom@grosjo.net mailto:jom@grosjo.net mailbox inbox text milan doveadm(jom@grosjo.net mailto:jom@grosjo.net): Info: Get last UID of INBOX = 315526 doveadm(jom@grosjo.net mailto:jom@grosjo.net): Info: Get last UID of INBOX = 315526 doveadm(jom@grosjo.net mailto:jom@grosjo.net): Info: Query: FLAG=AND doveadm(jom@grosjo.net mailto:jom@grosjo.net): Info: Query(1): add term(wilcard) : inbox doveadm(jom@grosjo.net mailto:jom@grosjo.net): Info: Query(2): add term(wilcard) : milan doveadm(jom@grosjo.net mailto:jom@grosjo.net): Info: Testing if wildcard doveadm(jom@grosjo.net mailto:jom@grosjo.net): Info: Query: set GLOBAL (no specified header) doveadm(jom@grosjo.net mailto:jom@grosjo.net): Info: Query : ( bcc:inbox OR body:inbox OR cc:inbox OR from:inbox OR message-id:inbox OR subject:inbox OR to:inbox ) AND ( bcc:milan OR body:milan OR cc:milan OR from:milan OR message-id:milan OR subject:milan OR to:milan ) doveadm(jom@grosjo.net mailto:jom@grosjo.net): Info: Query: 2 results in 1 ms // THIS IS WHEN BACKEND HAS FOUND RESULTS AND STOPPED d82b4b0f550d38593644000095331209 847 d82b4b0f550d38593644000095331209 1569 d82b4b0f550d38593644000095331209 2260 d82b4b0f550d38593644000095331209 2575 d82b4b0f550d38593644000095331209 2811 d82b4b0f550d38593644000095331209 2885 d82b4b0f550d38593644000095331209 3038 d82b4b0f550d38593644000095331209 3121 -> LOOPING FOREVER

On 2019-04-21 09:57, Timo Sirainen via dovecot wrote:

On 3 Apr 2019, at 20.30, Joan Moreau via dovecot mailto:dovecot@dovecot.org> wrote: doveadm search -u jom@grosjo.net mailto:jom@grosjo.net mailbox inbox text milan output

doveadm(jom@grosjo.net mailto:jom@grosjo.net): Info: Query : ( bcc:inbox OR body:inbox OR cc:inbox OR from:inbox OR message-id:inbox OR subject:inbox OR to:inbox OR uid:inbox ) AND ( bcc:milan OR body:milan OR cc:milan OR from:milan OR message-id:milan OR subject:milan OR to:milan OR uid:milan )

1 - The query is wrong

That's because fts_backend_xapian_lookup() isn't anywhere close to being correct. Try to copy the logic based on solr_add_definite_query_args().