# fts-dovecot plugin¶

## fts_dovecot_fs¶

• Default: <empty>

Define the location for the fts cache and indexes path on remote filesystems.

It must be somewhat synchronized with obox_fs and mail_location, see also Mail Location Settings.

It is strongly recommended to use fscache to speed up Obox and Dovecot FTS operation. It is recommended that the FTS and email fscaches point to DIFFERENT locations.

A simple example with local storage for FTS:

mail_plugins = \$mail_plugins fts fts_dovecot

plugin {
fts = dovecot
fts_dovecot_fs = posix:prefix=/var/fts/%u/
}


Example configurations for different object storage backends:

## fts_dovecot_filename_sizes¶

• Default: <empty>

Specifies whether or no filenames should contain the file size.

Example:

fts.D_238a58274822005cc3350000654d370e.000000b1-00000698.0001   # with size (0x698 == 1688 bytes)
fts.D_bc75a6128d5fff5b83070000654d370e.00000046.0001            # without size


The possible values are:

• yes: Include sizes in new triplets’ filenames (recommended for fresh installations)

• no: Do not include sizes in new triplets’ filenames

• yes-force: like yes, but running doveadm fts optimize will replace all triplets with new ones using sizes in the filenames

• no-force: like no, but running doveadm fts optimize will replace all triplets with new ones not using sizes in the filenames

## fts_dovecot_prefix¶

New in version v2.3.5.

• Default: no

Specifies how prefix search should be invoked. May not work with some filters.

Options:

• yes: equivalent to 0-255

• <num>-[<num>]: search strings with that length will be treated as prefixes (e.g. “4-“, “3-10”)

• no : no prefix searching is performed (this is the default)

## fts_dovecot_min_merge_l_file_size¶

New in version v2.3.5.

• Default: 128 kB

The smallest FTS triplet is getting recreated whenever indexing new mails until it reaches this size. Then the triplet becomes merged with the next largest triplet.

When fts-cache is used, this effectively controls how large the fts.L file can become in metacache until the FTS triplet is uploaded to object storage.

## fts_dovecot_mail_flush_interval¶

New in version v2.3.5.

• Default: 0 (none)

Upload locally cached FTS indexes to object storage every N new emails. This reduces the number of emails that have to be read after backend failure to update the FTS indexes, but at the cost of doing more writes to object storage.

The recommended value is 10. This will become the default in some future version.