From: Tomek Mrugalski Date: Thu, 19 Aug 2021 13:01:26 +0000 (+0200) Subject: [#2024] wordsmithing after review X-Git-Tag: Kea-1.9.11~75 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=eaf756b98c8bd90bfa33d35f593fe97a8946a409;p=thirdparty%2Fkea.git [#2024] wordsmithing after review --- diff --git a/doc/sphinx/arm/admin.rst b/doc/sphinx/arm/admin.rst index f04f2f0c90..4abd3836f4 100644 --- a/doc/sphinx/arm/admin.rst +++ b/doc/sphinx/arm/admin.rst @@ -381,7 +381,7 @@ Simple MySQL tweak to gain performance ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Changing the MySQL internal value ``innodb_flush_log_at_trx_commit`` from the default value -of ``1`` to ``2`` can result in a huge gain in Kea performance. In some deploments, the +of ``1`` to ``2`` can result in a huge gain in Kea performance. In some deployments, the gain was over 1000% (10 times faster when set to 2, compared to the default value of 1). It can be set per-session for testing: @@ -401,11 +401,11 @@ Be aware that changing this value can cause problems during data recovery after a crash, so we recommend checking the `MySQL documentation `__. With the default value of 1, MySQL writes changes to disk after every INSERT or UPDATE query -(in Kea terms, every time a client get a new or renews existing lease). When -``innodb_flush_log_at_trx_commit`` is set to 2, MySQL does write the changes at intervals -no longer than 1 second. Batching writes gives substantial performance boost. The trade-off, +(in Kea terms, every time a client get a new lease or renews an existing lease). When +``innodb_flush_log_at_trx_commit`` is set to 2, MySQL writes the changes at intervals +no longer than 1 second. Batching writes gives a substantial performance boost. The trade-off, however, is that in the worst case scenario all changes in the last second before crash -could be lost. Given the fact that Kea is a stable software and crashes very rarely, +could be lost. Given the fact that Kea is stable software and crashes very rarely, most deployments find it a beneficial trade-off. .. _pgsql-database: