Bug #27258 MySQL can't find so in plugin dir, does find it if in /lib/
Submitted: 19 Mar 2007 12:42 Modified: 24 Sep 2007 9:39
Reporter: Roland Bouman Email Updates:
Status: Closed Impact on me:
Category:MySQL Server: User-defined functions ( UDF ) Severity:S3 (Non-critical)
Version:5.1.16 OS:Linux (Linux)
Assigned to: CPU Architecture:Any
Tags: .so, /lib/, plugin dir, shared object file, udf

[19 Mar 2007 12:42] Roland Bouman
In MySQL 5.1, shared object files containing udf's should be placed in the plugin directory. However, a MySQL installed in a non-default basedir will not look in the plugin dir for the shared object file. Rather, it tries to locate the file in /lib/

How to repeat:
My mysql server is located here:


(entire tree from mysql on owned by user mysql, in group mysql)

Use udf_example.c from the sql subdirectory in a source distribution. Move to a convenient location. Compile using:

gcc -I/opt/mysql/5.1/16/mysql-5.1.16-beta-linux-i686-glibc23/include -shared udf_example.c -oudf_example.so

Find the plugin dir:

mysql> show variables like 'plugin_dir';
| Variable_name | Value                                                            |
| plugin_dir    | /opt/mysql/5.1/16/mysql-5.1.16-beta-linux-i686-glibc23/lib/mysql |

Find directory "mysql" not present under "lib", create one manually:

sudo mkdir /opt/mysql/5.1/16/mysql-5.1.16-beta-linux-i686-glibc23/lib/mysql

Copy the .so file there:

sudo cp udf_example.so /opt/mysql/5.1/16/mysql-5.1.16-beta-linux-i686-glibc23/lib/mysql

set permissions:

sudo chown -R mysql /opt/mysql/5.1/16/mysql-5.1.16-beta-linux-i686-glibc23/lib/mysql

sudo chgrp -R mysql /opt/mysql/5.1/16/mysql-5.1.16-beta-linux-i686-glibc23/lib/mysql

create a function from the library:

mysql> CREATE FUNCTION metaphon RETURNS STRING SONAME 'udf_example.so';
ERROR 1126 (HY000): Can't open shared library 'udf_example.so' (errno: 2 udf_example.so: cannot open shared object file: No such file or directory)

moving .so to /opt/mysql/5.1/16/mysql-5.1.16-beta-linux-i686-glibc23/lib/mysql/lib; /opt/mysql/5.1/16/mysql-5.1.16-beta-linux-i686-glibc23/lib/mysql; /opt/mysql/5.1/16/mysql-5.1.16-beta-linux-i686-glibc23/lib/mysql/bin or the data directory does not work either, and gives 
ERROR 1126 (HY000): Can't open shared library 'udf_example.so' (errno: 22 udf_example.so: cannot open shared object file: No such file or directory)

Moving the .so to  /lib does work.

(For most moves I had to use sudo mv, which would change owner and group; in each case, owner and group where reset to mysql)

Suggested fix:
Not sure really, I suspect it has to do with the non-default location of the mysql server. Have heard people for which it did seem to work with the server located in 

/usr/local/mysql (and the plugin dir in /usr/local/mysql/lib/mysql)
[19 Mar 2007 14:51] Sveta Smirnova
Thank you for the report.

Verified as described.
[24 Sep 2007 9:39] Roland Bouman
fixed as a result of http://bugs.mysql.com/bug.php?id=28341