问题
I searched about the topic subject and tested options, but I still cant increase the open-files-limit on my mariadb server that is used as remote database server for cpanel/whm server. here is s good reference http://duntuk.com/how-raise-ulimit-open-files-and-mysql-openfileslimit
I increased it in
/etc/my.cnf
open-files-limit=65550
here is some results
#ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 63471
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 65535
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 65535 virtual memory (kbytes, -v) unlimited file locks (-x) unlimited
#ulimit -Hn -Sn
open files (-n) 65535
open files (-n) 65535
cat /etc/systemd/system/mariadb.service.d/limits.conf
[Service]
LimitNOFILE=65500
cat /usr/lib/systemd/system/mariadb.service
[Unit]
Description=MariaDB database server
After=syslog.target
After=network.target
[Service]
Type=simple
User=mysql
Group=mysql
LimitNOFILE=infinity
LimitMEMLOCK=infinity
and still in mysql I get
show global variables like 'open%';
+------------------+-------+
| Variable_name | Value |
+------------------+-------+
| open_files_limit | 1024 |
+------------------+-------+
1 row in set (0.00 sec)
and im getting following error over and over after restart
60108 16:30:02 [ERROR] mysqld: Can't open file: './username_wp/wp_users.frm' (errno: 24)
160108 16:30:02 [ERROR] Error in accept: Too many open files
160108 16:30:04 [ERROR] Error in accept: Too many open files
160108 16:30:06 [ERROR] Error in accept: Too many open files
160108 16:30:11 [ERROR] mysqld: Can't open file: './username_db/strikes.frm' (errno: 24)
and here is the startup log of mariadb
[Warning] Could not increase number of max_open_files to more than 1024 (request: 132107)
回答1:
RH/CentOS mariadb integration is quiet confusing, using in some places mariadb as its name, mysqld elsewhere...
You should edit(or create) a .conf file in
/etc/systemd/system/mariadb.service.d/
For eg: /etc/systemd/system/mariadb.service.d/centreon.conf
Then edit it as kujiy suggested
[Service]
LimitNOFILE=320000
Don't forget to reload systemd services files:
# systemctl daemon-reload
Cedric
回答2:
This is an OS problem.
I think you have to increase the "hard limit" in /etc/security/limits.conf, something like this:
* hard nofile 65536
* soft nofile 16384
then use ulimit to increase the "soft limit".
回答3:
finally i find solution but without any reasonable cause ! i was running MariaDB 5.5 and all settings where fine but the soft limit did not goes more than 1024 ! i was thinking my mariadb is 10.0 as i freshly installed it
after i find out that its 5.5 i tried to upgrade it to v10.0 ! and then BOOM ! problem solved without any extra action or setting ( kernel setting allows maximum files limit as described in reference link )
i hope it help other peoples have same problem ( but after try all other required settings )
回答4:
You can see the official instruction in the mariadb.service file;
[root@db1 system]# cat /usr/lib/systemd/system/mariadb.service | grep exam -A 5
# For example, if you want to increase mariadb's open-files-limit to 10000,
# you need to increase systemd's LimitNOFILE setting, so create a file named
# "/etc/systemd/system/mariadb.service.d/limits.conf" containing:
# [Service]
# LimitNOFILE=10000
Though I think this should be written in the official manual...
回答5:
I have CentOS 7.3 with MariaDB 10.0.29 installed from official repo.
For some reason, systemd unit is named mysql and I had to create /etc/systemd/system/mysql.service.d/oioki.conf:
[Service]
LimitNOFILE=500000
Don't forget to run systemctl daemon-reload after that.
回答6:
I had this problem running RedHat Enterprise Linux 7.2 with Software Collections (SCL) and SystemD
rh-mariadb100-mariadb-server-10.0.20-1.el7.x86_64
In my case the hard limit was ok, but the soft limit was stuck on 1024
Summary of the old and new
old : RHEL6.x : MySQL : init.d : mysql_safe : 'root', mysqld : 'mysql'
new : RHEL7.x : MariaDB : SystemD : mysql_safe : 'mysql', mysqld 'mysql'
Note that the old initl.d wrapper script runs as root, but the new SystemD wrapper script runs as 'mysql'. This can cause mysql_safe to not make the call to ulimit. In my case setting LimitNOFILE in SystemD didn't help - all it did was increase the file limit for the wrapper, but NOT for the daemon itself. I found a two step process to get it working
Step 1 - re-instate the mysqld_safe section to the conf file so that mysql_safe will read it
sudo vi /etc/opt/rh/rh-mariadb100/my.cnf.d/mariadb-server.cnf
[mysqld_safe]
open_files_limit=2048
Step 2 - create a SystemD drop-in to start the wrapper as root (the daemon will still run as 'mysql'). Note that LimitNOFILE is commented out.
/etc/systemd/system
mkdir rh-mariadb100-mariadb.service.d
cd rh-mariadb100-mariadb.service.d
vi limits.conf
[Service]
#LimitNOFILE=2048
User=
Group=
Reload SystemD service files
systemctl daemon-reload
now restart the service, check value of open_files_limit in mysql client it should now say 2048 (new soft limit)
The proper solution would probably be to get rid of the wrapper and use native SystemD.
UPDATE it looks like this is fixed in the more recent version, which no longer uses the mysql_safe wrapper
rh-mariadb101-mariadb-10.1.19-6.el7.x86_64
回答7:
To increase open-files-limit in MySQL 5.6 on Centos 7 you must:
nano /usr/lib/systemd/system/mysqld.service
add at the end of the file:
LimitNOFILE=65535
LimitNPROC=65535
then:
systemctl daemon-reload
systemctl restart mysqld
Done! , I assume that for MariaDB is the same thing
回答8:
open_files_limit is dynamic value that depends on next params:
#my.cnf file
# max connections
max_connections = 64
# table_open_cache = max_connections * tables used in one transaction + 5
table_open_cache = 800
# table_definition_cache = all tables(50) + max_connections + 5
table_definition_cache = 400
# open_files_limit = table_open_cache * 1.4
open_files_limit = 1120
To check the value of open_files_limit run this command from mysql:
mysql> select @@open_files_limit;
...it will output:
+--------------------+
| @@open_files_limit |
+--------------------+
| 12903 |
+--------------------+
1 row in set (0.000 sec)
来源：https://stackoverflow.com/questions/34686072/cannot-increase-open-files-limit-in-mariadb-10-on-centos7