PureMessage reaction on loss of database connection

We currently run PureMessage using a locally clustered+mirrored SQL Server installation with an SQL server instance on each of the mailbox store hosts.

Any messages that enter the organization or leave the Exchange servers are additionally scanned on the mail relay servers, so PureMessage effectively only needs to be present to handle infected traffic between local Exchange users (happens almost never).

Since that installation was planned, however, other parts of the organization have grown a centrally administered SQL server installation. Hence we'd be happy to use an external SQL server instead of managing our own SQL server infrastructure locally on the Exchange servers.

However, the QoS guarantee for the central SQL server includes something like a "maybe inaccessible for a short time (few minutes) during cluster failover" disclaimer.

Given the operating range, we think we can actually live with "during this time, PureMessage does not scan any messages and operates in pass-through mode".

However, I cannot find any resources on this topic.

How does PureMessage react, when the SQL database connection is lost?

  • Does mail processing go on hold (not really an option)?
  • Do all mails transmitted during the SQL server downtime get marked as "unscanned" (acceptable)?
  • Does mail processing continue without virus scanning (bad security-wise, but more or less what we want)?

Perhaps someone who had this happen as part of an (unplanned) outtage can comment on this.

  • Hi, bumping this in case anyone else can answer as we have a similar scenario where we would like to know what happens when the SQL Server hosting the PureMessage DB for our Exchange DAG is restarted for scheduled maintenance.  Does PureMessage let all messages through in pass through mode?  Does PureMessage fall over and crash as no DB is available?  What happens?  Would be good to know before the event and before we have any annoyed end users with no mail service!

    Thanks

    Justin

     

    Peter Wullinger

    We currently run PureMessage using a locally clustered+mirrored SQL Server installation with an SQL server instance on each of the mailbox store hosts.

    Any messages that enter the organization or leave the Exchange servers are additionally scanned on the mail relay servers, so PureMessage effectively only needs to be present to handle infected traffic between local Exchange users (happens almost never).

    Since that installation was planned, however, other parts of the organization have grown a centrally administered SQL server installation. Hence we'd be happy to use an external SQL server instead of managing our own SQL server infrastructure locally on the Exchange servers.

    However, the QoS guarantee for the central SQL server includes something like a "maybe inaccessible for a short time (few minutes) during cluster failover" disclaimer.

    Given the operating range, we think we can actually live with "during this time, PureMessage does not scan any messages and operates in pass-through mode".

    However, I cannot find any resources on this topic.

    How does PureMessage react, when the SQL database connection is lost?

    • Does mail processing go on hold (not really an option)?
    • Do all mails transmitted during the SQL server downtime get marked as "unscanned" (acceptable)?
    • Does mail processing continue without virus scanning (bad security-wise, but more or less what we want)?

    Perhaps someone who had this happen as part of an (unplanned) outtage can comment on this.

     

  • In reply to JustinTL:

    I can answer you at least a few of the original questions, since we have tested turning of the connection to the SQL server before going into production.

    • Does mail processing go on hold (not really an option)?

    No

    • Do all mails transmitted during the SQL server downtime get marked as "unscanned" (acceptable)?

    No

    • Does mail processing continue without virus scanning (bad security-wise, but more or less what we want)?

     

    Still unclear. As far as we can tell, only the quarantaine and reporting stops working. We have not verified if virus scanning continues.

    JustinTL

    Hi, bumping this in case anyone else can answer as we have a similar scenario where we would like to know what happens when the SQL Server hosting the PureMessage DB for our Exchange DAG is restarted for scheduled maintenance.  Does PureMessage let all messages through in pass through mode?  Does PureMessage fall over and crash as no DB is available?  What happens?  Would be good to know before the event and before we have any annoyed end users with no mail service!

    Thanks

    Justin

    [...]

  • In reply to Peter Wullinger:

    That's great Peter, thank you.  My biggest concern was it affecting the the Exchange servers somehow and then them requiring rebooting or Exchange services restarting to bring them back to life and affecting end users.  If it's just a bit of reporting or quarentining that's lost for a few minutes then that's acceptable.

    Thanks

    Justin