Upgrade from Piwik 1.0 to 2.x Performance degradation (no replies)

Hi everybody,

Recently we got an upgrade from 1.0 to 2.0.3 facing some performances issues. Finally we upgraded to 2.2.2.

Currently we use Piwik on a quite large site (600K page visits/360K unique visitors/6.600K actions all values per day) and we noticed a huge performance degradation, moving from the older to the latest version, especially on the database.

We are focusing on the concurrent connections vs the DB seeing the 1.0 50-100 connections raised up to 1500 of the 2.x.x thus locking the DB.

We tried to work on MySQL parameters (current settings are "innodb_buffer_pool_size" = 65536, "innodb_flush_log_at_trx_commit" = 2), we made a memory upgrade of the server (from 32 GB to 64 GB) and tried to follow your guidelines to tune Piwik ( increasing "tracker_cache_file_ttl" = 7200, disabling some Tracker plugins like "PrivacyManager" and "Provider") but we still have the performance issue. At today we archive data hourly ("enable_browser_archiving_triggering" = 0) but we have to stop the batch because of the huge performance degradation.

Following the configuration data of the MySQL machine:

CPU: n. 2 Intel(R) Xeon(R) E5504 @ 2.00GHz (http://ark.intel.com/products/40711/Intel-Xeon-Processor-E5504-4M-Cache-2_00-GHz-4_80-GTs-Intel-QPI)
RAM: 64 GByte
STORAGE: root=54GByte (60% free) - data=356GByte (47% free) - var=9.7GByte (74% free) - boot=996MByte (93% free) - /dev/shm=16GByte (100% free) - /MYSQLDATA=166GByte (29% free)
OPERATIVE SYSTEM: Red Hat Enterprise Linux Server release 5.9.0.2 (Tikanga) 64bit
MYSQL SERVER VERSION: 5.5.10 MySQL Community Server (GPL)

Thanks in advance for your support.