1. Short overview
-----------------

Pinba (PHP Is Not A Bottleneck Anymore) is a statistics server using MySQL as an interface.
It accumulates and processes data sent over UDP by multiple PHP processes and 
displays statistics in a nice human-readable form of simple "reports", also providing 
read-only interface to the raw data in order to make possible generation of more 
sophisticated reports.

Pinba is not a debugging tool in a common sense, since you're not supposed to do 
debugging on production servers, but its main goal is to help developers to locate 
bottlenecks in realtime and direct developers' attention to the code that really needs it.

See "How it works" chapter below if you need more details.

2. Installation requirements
--------------------------------

Pinba requires MySQL 5.1.x sources to be built and MySQL 5.1.x installation to run.
MySQL 5.1 is the first version which supports pluggable storage engines, 
so older MySQL versions cannot and will never be supported.

Libraries required:
* Google Protocol Buffers - http://code.google.com/p/protobuf
* Judy - http://judy.sf.net
* libevent - http://monkey.org/~provos/libevent/
(this one may be already installed in your system, just make sure it's new enough (1.4+ is enough) and 
check that you have -devel package installed).

Optionally used:
* Hoard memory allocator - http://www.hoard.org

Using --with-hoard option you can add compiled-in Hoard support. It helps to reduce 
memory consumption (and Pinba is quite memory hungry when it comes to millions of timers).
2x smaller memory footprint with Hoard is what I regularly see.

3. Installation
---------------

Make sure you have all the required libraries installed and proceed with the compilation.

3.1. Compilation
----------------
Unpack Pinba archive and start the good old configure & make procedure:

# ./configure --with-mysql=/path/to/the/sources/of/mysql-5.1 --with-judy=/judy/prefix --with-protobuf=/protobuf/prefix --with-event=/event/prefix --libdir=/path/to/mysql/plugin/dir
# make install

--libdir option is required in order to get the library installed into the correct directory 
(but you can always put the lib there manually).
Usually the path looks like <MySQL install prefix>/lib/mysql/plugin, so if you've installed 
MySQL using /usr/local/mysql prefix, the path should be /usr/local/mysql/lib/mysql/plugin.


3.2. Plugin installation
------------------------

And then in MySQL console execute:

mysql> INSTALL PLUGIN pinba SONAME 'libpinba_engine.so';

I'd also suggest you to create a separate database, this way:

mysql> CREATE DATABASE pinba;

And then create the default tables:

# mysql -D pinba < default_tables.sql

If you did `make install` or used a precompiled package, look for default_tables.sql in /usr/share/pinba_engine directory.

4. How it works
---------------

Each PHP process creates a Protobuf message and sends it to the configured Pinba 
server on request shutdown. The packet is sent over UDP, so it doesn't affect PHP's 
performance in any way. This also means some packets may be lost, as UDP is not 
reliable by its nature, but that should not bother you much.

Pinba server listening to the configured port (see pinba_port setting) reads and decodes 
arriving Protobuf messages, adding them to the temporary pool. The temporary pool is needed 
to prevent too frequent locking of the main pool, which might slow down the queries.
Once in a while (see pinba_stats_gathering_period directive) Pinba locks down the main 
pool of records and adds the records from the temporary pool. It also drops outdated 
records (see pinba_stats_history directive) and updates indexes and base reports in the 
same moment. Tag reports are also updated, if any.
Both main and temporary pools are implemented as cyclic buffers of limited size, created 
on startup and never re-allocated, so newer records always overwrite older ones.

Well, this is all I had to say so far.
If you have any questions, feel free to ask them in the list - pinba-engine@googlegroups.com.
Send an empty email to pinba-engine+subscribe@googlegroups.com in order to subscribe.

Have fun.
