Revert "put mysql on a memory diet"

The diet seems to be too strict, jobs failing with "out of sort memory". Needs more investigation before resubmitting.

This reverts commit 1e66388c5f2b81b4fc5d544dbf5fde2935218bd0.

Change-Id: Ic10effaaf047eb3527082baab889772c5e57fa90
diff --git a/lib/databases/mysql b/lib/databases/mysql
index e2c8343..7bbcace 100644
--- a/lib/databases/mysql
+++ b/lib/databases/mysql
@@ -96,191 +96,10 @@
     iniset -sudo $my_conf mysqld bind-address "$SERVICE_LISTEN_ADDRESS"
     iniset -sudo $my_conf mysqld sql_mode TRADITIONAL
     iniset -sudo $my_conf mysqld default-storage-engine InnoDB
-
-    # the number of connections has been throttled to 256. In the
-    # event that the gate jobs report "Too many connections" it is
-    # indicative of a problem that could be the result of one of many
-    # things. For more details about debugging this error, refer
-    # https://dev.mysql.com/doc/refman/5.5/en/too-many-connections.html.
-    # Note that the problem may not ONLY be an issue with MySQL
-    # connections. If the number of fd's at the OS is too low, you
-    # could see errors manifest as MySQL "too many connections".
-    iniset -sudo $my_conf mysqld max_connections 256
+    iniset -sudo $my_conf mysqld max_connections 1024
     iniset -sudo $my_conf mysqld query_cache_type OFF
     iniset -sudo $my_conf mysqld query_cache_size 0
 
-    # Additional settings to put MySQL on a memory diet. These
-    # settings are used in conjunction with the cap on max_connections
-    # as the total memory used by MySQL can be simply viewed as
-    # fixed-allocations + max_connections * variable-allocations. A
-    # nifty tool to help with this is
-    # http://www.mysqlcalculator.com/. A short description of each of
-    # the settings follows.
-
-    # binlog_cache_size, determines the size of cache to hold changes
-    # to the binary log during a transaction, for each connection. For
-    # more details, refer
-    # https://dev.mysql.com/doc/refman/5.6/en/replication-options-binary-log.html#sysvar_binlog_cache_size
-    # When binary logging is enabled, a smaller binlog cache could
-    # result in more frequent flushes to the disk and a larger value
-    # would result in less flushes to the disk but higher memory
-    # usage. This however only has to do with large transactions; if
-    # you have a small transaction the binlog cache is necessarily
-    # flushed on a transaction commit. This is a per-connection cache.
-    iniset -sudo $my_conf mysqld binlog_cache_size 4K
-
-    # binlog_stmt_cache_size determines the size of cache to hold non
-    # transactional statements in the binary log. For more details,
-    # refer
-    # https://dev.mysql.com/doc/refman/5.6/en/replication-options-binary-log.html#sysvar_binlog_stmt_cache_size
-    # This cache holds changes to non-transactional tables (read:
-    # MyISAM) or any non-transactional statements which cause
-    # modifications to data (truncate is an example). These are
-    # written to disk immediately on completion of the statement or
-    # when the cache is full. If the cache is too small, you get
-    # frequent writes to the disk (flush) and if the cache is too
-    # large, it takes up more memory. This is a per-connection cache.
-    iniset -sudo $my_conf mysqld binlog_stmt_cache_size 4K
-
-    # bulk_insert_buffer_size for MyISAM tables that use a special
-    # cache for insert statements and load statements, this cache is
-    # used to optimize writes to the disk. If the value is set to 0,
-    # the optimization is disabled. For more details refer
-    # https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_bulk_insert_buffer_size
-    # We set this to 0 which could result in higher disk I/O (I/O on
-    # each insert block completion).
-    iniset -sudo $my_conf mysqld bulk_insert_buffer_size 0
-
-    # host_cache_size controls a DNS lookup optimization. For more
-    # details refer
-    # https://dev.mysql.com/doc/refman/5.6/en/host-cache.html
-    iniset -sudo $my_conf mysqld host_cache_size 0
-
-    # innodb_buffer_pool_size This is the size of the server wide
-    # buffer pool. It is the cache for all data blocks being used by
-    # the server and is managed as a LRU chain. Dirty blocks either
-    # age off the list or are forced off when the list is
-    # full. Setting this to 5MB (default 128MB) reduces the amount of
-    # memory used by the server and this will result in more disk I/O
-    # in cases where (a) there is considerable write activity that
-    # overwhelms the allocated cache, or (b) there is considerable
-    # read activity on a data set that exceeds the allocated
-    # cache. For more details, refer
-    # https://dev.mysql.com/doc/refman/5.6/en/innodb-parameters.html#sysvar_innodb_buffer_pool_size
-    iniset -sudo $my_conf mysqld innodb_buffer_pool_size 5M
-
-    # innodb_ft_cache_size and innodb_ft_total_cache_size control the
-    # per-connection full text search cache and the server wide
-    # maximum full text search cache. We should not be using full text
-    # search and the value is set to the minimum allowable. The former
-    # is a per-connection cache size and the latter is server
-    # wide. For more details, refer
-    # https://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_ft_cache_size
-    # and
-    # https://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_ft_total_cache_size
-    iniset -sudo $my_conf mysqld innodb_ft_cache_size 1600000
-    iniset -sudo $my_conf mysqld innodb_ft_total_cache_size 32000000
-
-    # innodb_log_buffer_size This buffer is used to buffer
-    # transactions in-memory before writing them to the innodb
-    # internal transaction log. Large transactions, or high amounts of
-    # concurrency, will cause the system to fill this faster and thus
-    # make the system more disk-bound. For more details, refer
-    # https://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_log_buffer_size
-    iniset -sudo $my_conf mysqld innodb_log_buffer_size 256K
-
-    # innodb_sort_buffer_size, This buffer is used for sorting when
-    # InnoDB is creating indexes. Could cause that to be slower, but
-    # only if tables are large. This is a per-connection setting. For
-    # more details, refer
-    # https://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_sort_buffer_size
-    iniset -sudo $my_conf mysqld innodb_sort_buffer_size 64K
-
-    # join_buffer_size, This buffer makes table and index scans
-    # faster. So this setting could make some queries more disk
-    # bound. This is a per-connection setting. For more details refer
-    # https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_join_buffer_size.
-    iniset -sudo $my_conf mysqld join_buffer_size 128
-
-    # key_buffer_size defines the index blocks used for MyISAM tables
-    # and shared between threads. This is a server wide setting. For
-    # more details see
-    # https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_key_buffer_size
-    iniset -sudo $my_conf mysqld key_buffer_size 8
-
-    # max_heap_table_size sets the maximum amount of memory for MEMORY
-    # tables (which we don't use). The value is set to 16k, the
-    # minimum allowed. For more details, see
-    # https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_max_heap_table_size
-    iniset -sudo $my_conf mysqld max_heap_table_size 16K
-
-    # net_buffer_length Each client has a buffer for incoming and
-    # outgoing data, both start with a size of net_buffer_length and
-    # can grow (in steps of 2x) upto a size of max_allowed_packet. For
-    # more details see
-    # https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_net_buffer_length
-    iniset -sudo $my_conf mysqld net_buffer_length 1K
-
-    # read_buffer_size, read_rnd_buffer_size are per-thread buffer
-    # used for scans on MyISAM tables. It is a per-connection setting
-    # and so we set it to the minimum value allowable. Same for
-    # read_rnd_buffer_size. For more details refer
-    # https://dev.mysql.com/doc/refman/5.6/en/server-system-variables.html#sysvar_read_buffer_size
-    # and
-    # https://dev.mysql.com/doc/refman/5.6/en/server-system-variables.html#sysvar_read_rnd_buffer_size
-    iniset -sudo $my_conf mysqld read_buffer_size 8200
-    iniset -sudo $my_conf mysqld read_rnd_buffer_size 8200
-
-    # sort_buffer_size when a sort is requested, it will be performed
-    # in memory in a buffer of this size (allocated per connection)
-    # and if the data exceeds this size it will spill to disk. The
-    # innodb and myisam variables are used in computing indices for
-    # tables using the specified storage engine. Since we don't
-    # dynamically reindex (except during upgrade) these values should
-    # never be material. Obviously performance of disk based sorts is
-    # worse than in memory sorts and therefore a high value here will
-    # improve sort performance for large data. For more details,
-    # refer:
-    # https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_sort_buffer_size
-    # and
-    # https://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_sort_buffer_size
-    # and
-    # https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_myisam_sort_buffer_size
-    iniset -sudo $my_conf mysqld sort_buffer_size 32K
-    iniset -sudo $my_conf mysqld innodb_sort_buffer_size 64K
-    iniset -sudo $my_conf mysqld myisam_sort_buffer_size 4K
-
-    # thread_cache_size specifies how many internal threads to cache
-    # for use with incoming connections. We set this to 0 whic means
-    # that each connection will cause a new thread to be created. This
-    # could cause connections to take marginally longer on os'es with
-    # slow pthread_create calls. For more details, refer
-    # https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_thread_cache_size
-    iniset -sudo $my_conf mysqld thread_cache_size 0
-
-    # thread_stack is the per connection stack size, the minimum is
-    # 128k and the default is 192k on 32bit and 256k on 64bit
-    # systems. We set this to 192k. Complex queries which require
-    # recursion, stored procedures or other memory intensive
-    # operations could exhaust this and generate a very characteristic
-    # failure ("stack overflow") which is cleanly detected and the
-    # query is killed. For more details see
-    # https://dev.mysql.com/doc/refman/5.6/en/server-system-variables.html#sysvar_thread_stack
-    iniset -sudo $my_conf mysqld thread_stack 196608
-
-    # tmp_table_size is the maximum size of an in-memory temporary
-    # table. Temporary tables are created by MySQL as part of a
-    # multi-step query plan. The actual size of the temp table will be
-    # the lesser of tmp_table_size and max_heap_table_size. If a
-    # temporary table exceeds this size, it will be spooled to disk
-    # using the internal_tmp_disk_storage_engine (default
-    # MyISAM). Queries that often generate in-memory temporary tables
-    # include queries that have sorts, distinct, or group by
-    # operations, also queries that perform IN joins. For more details
-    # see
-    # https://dev.mysql.com/doc/refman/5.7/en/server-system-variables.html#sysvar_tmp_table_size
-    iniset -sudo $my_conf mysqld tmp_table_size 1K
-
     if [[ "$DATABASE_QUERY_LOGGING" == "True" ]]; then
         echo_summary "Enabling MySQL query logging"
         if is_fedora; then