4

We have a iWstack Cloud Service, with a main space of 100GB and 20GB Side Storge.

NewRelic is always telling me that the main Space is full.

I check what is using this space with:

sudo du -a /var/www | sort -n

but everything looks healthy.

then I start flushing cache all around.

and notice that , when I do :

RESET QUERY CACHE; RESET MASTER;

and restarting NGINX and PHP5 will free space.

Is there any configuration on my.cnf that I'm missing ???

UPDATE

my.cnf:

# MariaDB database server configuration file.
#
# You can copy this file to one of:
# - "/etc/mysql/my.cnf" to set global options,
# - "~/.my.cnf" to set user-specific options.
# 
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html

# This will be passed to all mysql clients
# It has been reported that passwords should be enclosed with ticks/quotes
# escpecially if they contain "#" chars...
# Remember to edit /etc/mysql/debian.cnf when changing the socket location.
[client]
port        = 3306
socket      = /var/run/mysqld/mysqld.sock

# Here is entries for some specific programs
# The following values assume you have at least 32M ram

# This was formally known as [safe_mysqld]. Both versions are currently parsed.
[mysqld_safe]
socket      = /var/run/mysqld/mysqld.sock
nice        = 0

[mysqld]
#
# * Basic Settings
#
user        = mysql
pid-file    = /var/run/mysqld/mysqld.pid
socket      = /var/run/mysqld/mysqld.sock
port        = 3306
basedir     = /usr
datadir     = /media/db/mysql
tmpdir      = /tmp
lc_messages_dir = /usr/share/mysql
lc_messages = en_US
skip-external-locking
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address        = 127.0.0.1
#
# * Fine Tuning
#
max_connections     = 100
connect_timeout     = 5
wait_timeout        = 600
max_allowed_packet  = 16M
thread_cache_size       = 128
sort_buffer_size    = 4M
bulk_insert_buffer_size = 16M
tmp_table_size      = 32M
max_heap_table_size = 32M
#
# * MyISAM
#
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched. On error, make copy and try a repair.
myisam_recover          = BACKUP
key_buffer_size     = 128M
#open-files-limit   = 2000
table_open_cache    = 400
myisam_sort_buffer_size = 512M
concurrent_insert   = 2
read_buffer_size    = 2M
read_rnd_buffer_size    = 1M
#
# * Query Cache Configuration
#
# Cache only tiny result sets, so we can fit more in the query cache.
query_cache_limit       = 128K
query_cache_size        = 64M
# for more write intensive setups, set to DEMAND or OFF
#query_cache_type       = DEMAND
#
# * Logging and Replication
#
# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
# As of 5.1 you can enable the log at runtime!
#general_log_file        = /var/log/mysql/mysql.log
#general_log             = 1
#
# Error logging goes to syslog due to /etc/mysql/conf.d/mysqld_safe_syslog.cnf.
#
# we do want to know about network errors and such
log_warnings        = 2
#
# Enable the slow query log to see queries with especially long duration
#slow_query_log[={0|1}]
slow_query_log_file = /var/log/mysql/mariadb-slow.log
long_query_time = 10
#log_slow_rate_limit    = 1000
log_slow_verbosity  = query_plan

#log-queries-not-using-indexes
#log_slow_admin_statements
#
# The following can be used as easy to replay backup logs or for replication.
# note: if you are setting up a replication slave, see README.Debian about
#       other settings you may need to change.
#server-id      = 1
#report_host        = master1
#auto_increment_increment = 2
#auto_increment_offset  = 1
log_bin         = /var/log/mysql/mariadb-bin
log_bin_index       = /var/log/mysql/mariadb-bin.index
# not fab for performance, but safer
#sync_binlog        = 1
expire_logs_days    = 10
max_binlog_size         = 100M
# slaves
#relay_log      = /var/log/mysql/relay-bin
#relay_log_index    = /var/log/mysql/relay-bin.index
#relay_log_info_file    = /var/log/mysql/relay-bin.info
#log_slave_updates
#read_only
#
# If applications support it, this stricter sql_mode prevents some
# mistakes like inserting invalid dates etc.
#sql_mode       = NO_ENGINE_SUBSTITUTION,TRADITIONAL
#
# * InnoDB
#
# InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.
# Read the manual for more InnoDB related options. There are many!
default_storage_engine  = InnoDB
# you can't just change log file size, requires special procedure
#innodb_log_file_size   = 50M
innodb_buffer_pool_size = 256M
innodb_log_buffer_size  = 8M
innodb_file_per_table   = 1
innodb_open_files   = 400
innodb_io_capacity  = 400
innodb_flush_method = O_DIRECT
#
# * Security Features
#
# Read the manual, too, if you want chroot!
# chroot = /var/lib/mysql/
#
# For generating SSL certificates I recommend the OpenSSL GUI "tinyca".
#
# ssl-ca=/etc/mysql/cacert.pem
# ssl-cert=/etc/mysql/server-cert.pem
# ssl-key=/etc/mysql/server-key.pem



[mysqldump]
quick
quote-names
max_allowed_packet  = 16M

[mysql]
#no-auto-rehash # faster start of mysql but no tab completition

[isamchk]
key_buffer      = 16M

#
# * IMPORTANT: Additional settings that can override those from this file!
#   The files must end with '.cnf', otherwise they'll be ignored.
#
!includedir /etc/mysql/conf.d/
2
  • I wrote this article -maybe it will help you to investigate space usage main.org.ua/linux-check-disk-space-usage Commented Aug 17, 2015 at 19:53
  • Let's disable query cache query_cache_type=0;query_cache_size=0; and keep monitoring how big this directory /var/log/mysql/ is.
    – Anatoly
    Commented Aug 18, 2015 at 6:30

1 Answer 1

3

MySQL query cache has been originally designed 13 years ago, since then it didn't get an appropriate adaptation for newer software and hardware. Due to Percona experts recommendation, keep it turned off all the time:

query_cache_size: the query cache is a well known bottleneck that can be seen even when concurrency is moderate. The best option is to disable it from day 1 by setting query_cache_size = 0 (now the default on MySQL 5.6) and to use other ways to speed up read queries: good indexing, adding replicas to spread the read load or using an external cache.

But this is pure performance recommendation, query cache doesn't consume hard drive space until it is really swapped.

What does reset master do for you, MySQL docs says:

RESET MASTER removes all binary log files that are listed in the index file, leaving only a single, empty binary log file with a numeric suffix of .000001, whereas the numbering is not reset by PURGE BINARY LOGS.

Share your my.cnf configuration to get more detailed instruction what to do next but if you say Reset Master helps the binary logs setup incorrectly.

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