
There is a race condition between the addition of the DCB into epoll and the execution of the event that initiates the protocol pointer for the DCB and sends the handshake to the client. If a hangup event would occur before the handshake would be sent, it would be possible that the DCB would get freed before the code that sends the handshake is executed. By picking the worker who owns the DCB before the DCB is placed into the owner's epoll instance, we make sure no events arrive on the DCB while the control is transferred from the accepting worker to the owning worker.
MaxScale by MariaDB Corporation
The MariaDB Corporation MaxScale is an intelligent proxy that allows forwarding of database statements to one or more database servers using complex rules, a semantic understanding of the database statements and the roles of the various servers within the backend cluster of databases.
MaxScale is designed to provide load balancing and high availability functionality transparently to the applications. In addition it provides a highly scalable and flexible architecture, with plugin components to support different protocols and routing decisions.
For a detailed overview of what MaxScale can do, read the MaxScale page on the MariaDB website.
An Google Group exists for MaxScale that can be used to discuss ideas, issues and communicate with the MaxScale community.
We're also on the #maria and #maxscale channels on FreeNode.
Please report all feature requests, improvements and bugs in the MariaDB Jira.
Getting Started
Read the Documentation Overview for a list of all MaxScale documents.
Documentation
The official documentation can be found on the MariaDB Knowledge Base.
A MaxScale Troubleshooting Guide can be found on the MariaDB Knowledgebase. It answers common questions encountered when installing and using MaxScale.
The documentation can also be found in the Documentation directory of the source tree.
Contributing Code
Read the Contributing page on the wiki for more information on how to do pull request and where to do them.