Prefetch mechanism for high performance LDAP-based SMTP mail routing
Publication Date: 2010-May-04
The IP.com Prior Art Database
The present publication discloses a simple yet powerful prefetch mechanism for efficient LDAP-based routing of high volume SMTP traffic with popular MTAs such as Postfix or Sendmail .
Prefetch mechanism for high performance LDAP -based SMTP mail routing
LDAP-based mail routing allows a central directory service to control the flow of mail delivery within an organization, without the hassle of hard-coded tables or the lack of granularity from DNS MX records. This is simple to implement (supported by major MTAs and LDAP servers), easy to change (if carefully planned) when user accounts move or mail servers structure changes within the administrative domain.
A drawback of such an approach in large, high volumes organizations is performance, especially during those well-known traffic bursts that occur in messaging systems at peak hours. An LDAP query request is being produced by SMTP MTA each time a message is received, this generates a huge strain on corporate directory servers infrastructure, adversely impacting business applications and user experience (e.g. response time for authentication and/or authorization). Alternatives such as dedicated LDAP infrastructure or co-located LDAP server replica with each SMTP MTA alleviate this problem, but at a cost (additional hardware and administration burden).
We envision a lightweight yet powerful prefetch mechanism taking advantage of the highly optimized built-in map (e.g. hash lookup table) feature of popular MTAs such as Postfix or Sendmail.
A batch process periodically retrieves all the tuples (SMTP address, mailHost) from the corporate LDAP infrastructure and builds a SMTP routing table for use by...