Hello, As part of the work to address the most problematic (read "slow") parts of OpenSIPS, several improvements were done on the DB areas (performing DB queries).
The end result is a 25% boost in DB queries - a 25% less time spent in running DB queries (see the test results). 1. Prepared statements ======================= Starting with OpenSIPS 1.5.0 the internal DB API provides support for prepared statements. First DB module to implement prepared statements is DB_MYSQL module. See more about the concept of prepared statements in MySQL : http://dev.mysql.com/doc/refman/5.0/en/sql-syntax-prepared-statements.html A very good overview on Prepared Statements, that may help you in understating the advantages and disadvantages of prepared statements can be found at http://www.mysqlperformanceblog.com/2006/08/02/mysql-prepared-statements/. The current implementation is based on an original patch submited by Victor Gamov; the patch was completely reworked, re-designed and improved. 2. Memory Fragmentation ======================== A complete rework of the structures from internal DB API was done in order to reduce the number of memory fragments used by a DB result: previous number = 1 + 2 + no_cols + 1 + no_rows current number = 3 The number of memory fragments is now constant and what is more important is the fact that we avoid keep allocating very small chunks (like 8 bytes). This will reduce the fragmentation of the private memory due of continues DB queries -> OpenSIPS is now a real long distance runner, with no side effect or performance decrease in time. TESTS AND MEASUREMENTS ======================== A set of tests were conducted in order to determine the real gain of prepared statements. The tests tried to cover various case - combinations between complexity of a query and the amount of data transfered by a query. Following the measurement with the new prepared statements a 25 % increase in performance. See the entire set of tests as well as the result interpretation: http://www.opensips.org/pmwiki.php?n=Resources.TestsPrepareStatements Best regards, Bogdan _______________________________________________ News mailing list [email protected] http://lists.opensips.org/cgi-bin/mailman/listinfo/news
