Scalable Email Design
A scalable enterprise email solution powering more than 500 millions users worldwide with ability that can span smaller, on-premise implementations to the cloud.
What is Scalable Design
The Zimbra Collaboration Suite (ZCS) architecture is designed for scale in a distributed environment and today it host many millions of mailboxes world-wide. Together with Cloudhappen Zimbra Professional Service team, ZCS has been deployed in Malaysia and ASEAN region on larger-scale format, including end user deployments upwards of 100 thousand mailboxes and hosted/internet service provider/telcos deployments of more than 1 million mailboxes.
Zimbra software offers multi-server infrastructure setup, the decoupling of components and other well-honed distributed systems techniques like clustering, partitioning, automated replication, data dependent routing, load balancing, and failover. Overall, these techniques have proven (e.g., Google, Yahoo!,Amazon, etc.) to scale well beyond the reach of more centralized architectures that tend to rely on stateless processing and very-large databases.
Some the more important techniques that give Zimbra its unique capabilities :
A single large-scale deployment can run over 100,000s of users with 100 messages a day per user. These substantial workloads are made possible with a distributed design, clustering with multi-server scheme and techniques like data dependent routing and load balancing.
Partitioning and Distribution
Of paramount importance to scaling is partitioning. Servers can be specialized to solve some subset of the bigger problem. Partitioning techniques include the vertical partitioning of functional tasks and the horizontal partitioning of data and the associated processing.
Multi Server Environment
Zimbra architecture allows the opportunity to separate all major components of a email system into multi-server environment. LDAP, MTA, Proxy, Mailstore and Webapp services can be either on one single machine or separate machines.
LDAP configuration data is fully replicated to as many replica hosts as are required to meet performance and availability requirements. LDAP replica hosts may be collocated with other ZCS servers or “vertically partitioned” to dedicated servers.
Cloudhappen approach to building large scale email systems building large scale email systems consists of these elements working together one way or another :