IMAP Archive Configuration
Once installed, you may configure the following parameters in the /etc/obm-imap-archive/obm-imap-archive.ini
file:
-
partition_suffix the Cyrus archive partition suffix, default value archive
-
batch_size default value 20
-
transaction_timeout_in_seconds default value 3600
Batch size
IMAP Archive process copies emails by batch. Rather than copying all emails in one IMAP command, it’s safer and more flexible to copy them by batches.
For example, when IMAP Archive process has to copy 1000 emails from a folder, it will split the IMAP copy command in 50 IMAP copy commands:
-
copy emails 1 to 20
-
copy emails 21 to 40
-
…
This configuration value is used to determine the number of emails copied in one batch.
This value has some impact in performances, a higher value should be faster.
But if a problem occurs during the treatment on a folder, the next treatment may duplicate some emails on this folder less than the batch size.
The default value is a good compromise between the performance and the potential number of duplicated emails.
Transaction timeout
This configuration value is used to define the transaction timeout to the database.
When processing, a transaction is opened per folder. This means that when archiving a huge amount of emails on a folder, transaction timeout may be reached.
As only one archive process is running at the same time on a domain, and this process is persisting only data in it’s own tables; we can use a huge value on this parameter, such as the default (one hour).