Oracle 5.0 Reference Manual page 1449

MySQL Proxy FAQ
The MySQL network protocol does not allow passwords to be sent in cleartext, all you could capture is
the encrypted version.
16.7.6.20: Are there tools for isolating problems? How can someone figure out whether a
problem is in the client, the database, or the proxy?
You can set a debug script in the proxy, which is an exceptionally good tool for this purpose. You can
see very clearly which component is causing the problem, if you set the right breakpoints.
16.7.6.21: Is MySQL Proxy similar to what is provided by Java connection pools?
Yes and no. Java connection pools are specific to Java applications, MySQL Proxy works with
any client API that talks the MySQL network protocol. Also, connection pools do not provide any
functionality for intelligently examining the network packets and modifying the contents.
16.7.6.22: So authentication with connection pooling has to be done at every connection? What
is the authentication latency?
You can skip the round-trip and use the connection as it was added to the pool. As long as the
application cleans up the temporary tables it used. The overhead is (as always) around 400
microseconds.
16.7.6.23: If you have multiple databases on the same box, can you use proxy to connect to
databases on default port 3306?
Yes, MySQL Proxy can listen on any port, provided that none of the MySQL servers are listening on
the same port.
16.7.6.24: What about caching the authorization information so clients connecting are given
back-end connections that were established with identical authorization information, thus
saving a few more round trips?
There is an [1404] option that provides this functionality.
--proxy-pool-no-change-user
16.7.6.25: Is there any big web site using MySQL Proxy? For what purpose and what
transaction rate have they achieved?
Yes, gaiaonline. They have tested MySQL Proxy and seen it handle 2400 queries per second through
the proxy.
16.7.6.26: How does MySQL Proxy compare to DBSlayer?
DBSlayer is a REST->MySQL tool, MySQL Proxy is transparent to your application. No change to the
application is needed.
16.7.6.27: I tried using MySQL Proxy without any Lua script to try a round-robin type load
balancing. In this case, if the first database in the list is down, MySQL Proxy would not connect
the client to the second database in the list.
This issue is fixed in version 0.7.0.
16.7.6.28: Is it "safe" to use with proxy scripts?
LuaSocket
You can, but it is not advised because it may block.
16.7.6.29: How different is MySQL Proxy from DBCP (Database connection pooling) for Apache
in terms of connection pooling?
Connection Pooling is just one use case of the MySQL Proxy. You can use it for a lot more and it works
in cases where you cannot use DBCP (for example, if you do not have Java).
16.7.6.30: MySQL Proxy can handle about 5000 connections, what is the limit on a MySQL
server?
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