Loading ...
Sorry, an error occurred while loading the content.

Re: Transport maps in MySQL

Expand Messages
  • Noel Jones
    ... If the transport table is unavailable, no mail will flow -- incoming mail will be deferred, mail in the queue will be temp-failed. There is no cache[1].
    Message 1 of 7 , Mar 7, 2013
    • 0 Attachment
      On 3/7/2013 2:17 PM, Alfredo Saldanha wrote:
      >> The transport table is a critical table used by pretty much every
      >>part of postfix (by way of the trivial_rewrite service). If the
      >>mysql database is unavailable, no mail will flow. If the lookups
      >>are slow, all postfix performance will suffer.
      >
      > In case of mysql connection drop, Postfix doesn't use the last
      > transport information ?
      > And another stuffs that use MySQL, like virtual aliases, users, etc.
      > the message will be rejected ?


      If the transport table is unavailable, no mail will flow -- incoming
      mail will be deferred, mail in the queue will be temp-failed. There
      is no cache[1].

      The transport table is particularly performance sensitive because
      it's used by the single-threaded trivial_rewrite service, which is
      referenced by every part of postfix. For a
      high-volume/high-performance server, it is recommended that
      transport tables use a local hash:, or better, cdb: file. This
      doesn't mean you can't use mysql, but it will require some care to
      insure availability and performance.

      As a general rule, when postfix references ANY table (not just
      mysql), if that table is unavailable an error will be issued and
      mail will be deferred until the table is again working. But not all
      tables are used by all postfix functions, and not all tables have
      the same impact on performance as transport.


      [1] there is a 1-element result cache to prevent postfix from
      looking up the same key repeatedly. This will not prevent table
      errors, nor is it intended to.




      -- Noel Jones
    Your message has been successfully submitted and would be delivered to recipients shortly.