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I'm trying to run a compiled 32-bit binary on a 64-bit CentOS 5.3 (based on RedHat 4.1.2) host. The binary complains about inability to find libmysqlclient.so.15. Such a file exists on the server, but it's 64-bit and therefore not good.

Can I install the 32-bit MySQL client libraries on the host? Preferably in the official way (i. e. via a repository). If not, what about a hackish way?

Also, is this a proper venue for such a question?

EDIT: here's an article that confirms that you cannot mix and match bitness within one process. But its recipe is not applicable to CentOS.

Wikipedia states that RHEL, which CentOS derives from, is capable of having a full 32-bit userland running along 64-bit... There are already some 32-bit libraries on the system - libc and such. Just not MySQL.

I can run other 32-bit binaries that don't link to libmysqlclient.

Somewhat related.

EDIT: yum search mysql says the following:

Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirror.symnds.com
 * extras: mirror.symnds.com
 * updates: mirror.wiredtree.com
addons                                                   | 1.9 kB     00:00
base                                                     | 1.1 kB     00:00
extras                                                   | 1.9 kB     00:00
updates                                                  | 1.9 kB     00:00
Excluding Packages in global exclude list
Finished
================================ Matched: mysql ================================
mod_auth_mysql.x86_64 : Basic authentication for the Apache web server using a
                      : MySQL database.
qt-MySQL.x86_64 : MySQL drivers for Qt's SQL classes.
MySQL-bench.x86_64 : MySQL - Benchmarks and test system
MySQL-client.x86_64 : MySQL - Client
MySQL-devel.x86_64 : MySQL - Development header files and libraries
MySQL-python.x86_64 : An interface to MySQL
MySQL-server.x86_64 : MySQL: a very fast and reliable SQL database server
MySQL-shared.x86_64 : MySQL - Shared libraries
apr-util-mysql.x86_64 : APR utility library MySQL DBD driver
bytefx-data-mysql.x86_64 : MySQL database connectivity for Mono
freeradius-mysql.x86_64 : MySQL bindings for freeradius
freeradius2-mysql.x86_64 : MySQL support for freeradius
libdbi-dbd-mysql.x86_64 : MySQL plugin for libdbi
pdns-backend-mysql.x86_64 : MySQL backend for pdns
pure-ftpd.x86_64 : Lightweight, fast and secure FTP server
qt4-mysql.x86_64 : MySQL drivers for Qt's SQL classes
rsyslog.x86_64 : Enhanced system logging and kernel message trapping daemon
rsyslog-mysql.x86_64 : MySQL support for rsyslog
unixODBC.i386 : A complete ODBC driver manager for Linux
unixODBC.x86_64 : A complete ODBC driver manager for Linux
unixODBC64.x86_64 : A complete ODBC driver manager for Linux
Community
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Seva Alekseyev
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    And why aren't you able to use the 64-bit client? – MDMarra May 11 '12 at 17:01
  • Can you really use 64-bit libraries in 32-bit executables? Thought not. How are they going to agree on pointer size? – Seva Alekseyev May 11 '12 at 17:07
  • HOW it is done is indeed implementation dependent and I am not from the RH world, but it is definitely possible. In the (unlikely) worst case some things will have to be manually installed, or the binary will need to run in a 32 bit chroot. – rackandboneman May 11 '12 at 17:34
  • If that's possible, how come the loader cannot automagically hook the executable up with the 64-bit client library that's already there? – Seva Alekseyev May 11 '12 at 17:52

2 Answers2

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How do I install 32-bit libmysqlclient.so?

1. Installation

Your MySQL installation could have come from different sources. It could be an rpm that came with the distribution or a Sun/Oracle rpm or it could have been built from sources.

 rpm -q --whatprovides $(which mysql)

should tell you the name of the package like

  1. MySQL-client-...
  2. mysql-5.0...
  3. mysql-community-server-client
  4. mysql-5.1...
  5. no package provides /usr/bin/mysql.

On CentOS the first two options are most likely. MySQL-client-5.0 is a Sun/Oracle RPM and mysql-5.0 could have come from the distribution. Use rpm -q --info <package_name> to get extended information and verify that the Vendor: line confirms the hypothesis.

Here is a typical Vendor line:

Name        : MySQL-shared-community       Relocations: (not relocatable)
Version     : 5.0.96                       Vendor: Oracle and/or its affiliates

1.1 MySQL from Sun/Oracle RPMs

If your mysql installation comes from Sun/Oracle, go to MySQL Community server download page, select among Generally Available (GA) releases the one that has mysql 5.0 version and 32-bit architecture, choose MySQL-shared-community package, download and install it with rpm -i. This package provides exactly the /usr/lib/libmysqlclient.so.15 library.

1.2 mysql from CentOS

In CentOS5 libmysqlclient belongs to the mysql package. 

yum install mysql.i386

should do the trick.

In CentOS6 it was moved to a separate mysql-libs package.

2. Testing

After installing the library, check if dynamic library dependencies are resolved correctly:

ldd <your_binary> | grep libmysqlclient

should return something like

libmysqlclient.so.15 => /usr/lib/mysql/libmysqlclient.so.15

If you want to know what provides a 32-bit version of a specific 64-bit library, you could use rpm -q --whatprovides /path/to/your/lib64/library to determine the name of the package. Then replace x86_64 with i686 in the name to get the name of the 32-bit counterpart. Use yum search to verify if the package is provided by the repositories you have subscribed to.

Dmitri Chubarov
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  • Says `No package mysql-libs.i686 available.` – Seva Alekseyev Sep 28 '12 at 16:26
  • Neither mysql-libs.i386 nor mysql.i386 is available, either. – Seva Alekseyev Sep 28 '12 at 17:34
  • Edited the question. There's only one i386 package there, and it's unixODBC.i386. – Seva Alekseyev Sep 28 '12 at 18:54
  • @SevaAlekseyev My quess is that mysql was installed on the machine from Sun/Oracle rpms instead of the CentOS ones and CentOS rpms are on the exlcude list. You could check which version of x86_64 rpms is installed with `rpm -q MySQL-client` and get a corresponding i386 rpm from [MySQL Community server dowlnoads](http://dev.mysql.com/downloads/mysql/5.5.html?current_os=7) – Dmitri Chubarov Sep 29 '12 at 03:41
0

Can I install the 32-bit MySQL client libraries on the host?

Yes. Redhat installs the 32bit libraries in /usr/lib, and the 64bit libraries go to /usr/lib64. The OS will automatically load the appropriate library when the software is run.

Nicholas
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