The splitlogs Binary
Last modified: July 19, 2022
To use the
/usr/local/cpanel/bin/splitlogs binary, you must enable the Enable Piped Apache Logs setting in the Piped Log Configuration section of WHM’s Apache Configuration interface (WHM » Home » Server Configuration » Apache Configuration).
/usr/local/cpanel/bin/splitlogs binary optimizes your resources and performance when you create Apache logs. For example, the
/usr/local/cpanel/bin/splitlogs binary can close file handles without the need to restart Apache. This greatly improves log processing and bandwidth processing performance.
Apache’s default behavior opens and writes to both a byte log file and an access log file for each virtual host in Apache’s configuration file. Because of this, the number of open log files equals twice the number of virtual hosts in Apache’s
/usr/local/apache/conf/httpd.conf file. However, to reduce Apache’s memory consumption, cPanel & WHM uses Apache’s piped logs functionality with the
splitlogs binary to process Apache log information. The
splitlogs binary only opens and writes to a single log file when a visitor accesses a virtual host.
cPanel & WHM runs two instances of the splitlogs binary: one to manage the byte log files, and the other to manage the access log files. The
splitlogs binary extracts the domain name and port from the Apache logs, and uses this information as a space-separated line in the log file. This information determines the log file’s name, which the system writes to either a specified directory, or to the default location for Apache logs in the
splitlogsbinary will only write to Apache’s byte and access log file. It will not write to the domain log file for the shared IP address.
To call the
splitlogs binary from the command line, use the following syntax:
Use the following arguments when you call the
splitlogs binary. If you do not specify an argument, the
splitlogs binary uses the indicated default value.
||This argument verifies that the
Apache configuration arguments
||Pass this argument with a value to specify the directory in which you wish to store Apache log files. This value defaults to the
||Pass this argument with a value to specify the suffix to use with unencrypted (non-SSL) Apache access logs. This value defaults to an empty string.||
||Pass this argument with a value to specify the suffix to use with SSL Apache access logs. This value defaults to the
||Pass this argument with a value to specify the port on which the system makes SSL connections. The
Port 443 is the standard default port number for encrypted (HTTPS) Apache requests.
||Pass this argument with a value to specify the server’s hostname. By default, Apache routes requests that do not have a virtual host to the default log, rather than to a separate domain log. This argument allows you to specify the server’s hostname to cause the
||Pass this argument with a value to specify the path to the default access log file in which the system logs requests without a virtual host. This argument and the
Performance tweaking arguments
||Pass this argument with a value to specify the maximum number of log files that the splitlogs binary can open at the same time.
||Pass this argument with a value to specify whether to enable buffered file writing.
More about the
--maxopenvalue to the default value (
--maxopen argument specifies the maximum number of log files to open at the same time. Use this argument to optimize either speed or resources:
- If you set a low
splitlogsbinary opens and closes files more often, which reduces performance.
- If you set a high
splitlogsbinary requires more system resources and operating system file handles, which increases the overall system load. This load increases if you also enable buffered file writing with the
- We recommend that you use the current pattern of access to sites on your system in order to determine the
splitlogslog file provides additional information that may help you determine this value. For more information, read the Notes about performance concerns section below.
splitlogs binary only closes files under the following circumstances:
- If the maximum number of files are already open and the
splitlogsbinary needs to write to a new file, the system closes the oldest file and open the new file.
splitlogsbinary closes some open files during log and bandwidth processing.
splitlogsbinary closes all of the open files when Apache restarts.
More about the
--buffer argument allows you to specify whether to enable buffered file writing. Under most conditions, the
splitlogs binary uses buffered file writing by default. However, if the
/var/cpanel/conserve_memory flag file exists, the system disables buffered filing writing by default. The
--buffer argument overrides these defaults.
- If you enable buffered file writing, the
splitlogsbinary writes to individual log files faster, but requires more memory for each open log file.Warning:
- To experience this performance increase, the system must have extra memory and the server must possess a light load to allow it to flush buffers in a timely fashion. If the system becomes overloaded or does not have extra memory, buffered file writing decreases overall performance.
- If the
splitlogsbinary terminates ungracefully before the buffers flush, you may experience some data loss.
- If you disable buffered file writing, the
splitlogsbinary requires substantially less memory. For example, on a system with an operating system buffer of 4,000 file handles and a
1024, the system uses 4 MB of memory for each
The splitlogs configuration file
When cPanel & WHM rebuilds Apache’s configuration file, the system examines the
/var/cpanel/conf/splitlogs.conf file. The system uses the contents of this file to set command line arguments for
CustomLog directives in Apache’s
The configuration file contains line-delimited
key=value pairs. The key entries are the same as the command line arguments.
After you specify custom directives for the
/var/cpanel/conf/splitlogs.conf file, you must rebuild and restart Apache. To do this, run the following
Notes about performance concerns
splitlogsbinary writes information to its log file whenever it reaches 1,000 times its file handle limit. These log messages indicate how often the
splitlogsbinary opens and closes log files.
- If you do not encounter these messages in the
splitlogsbinary’s log file, reduce the
- If you encounter an unusually high number of these messages in the
splitlogbinary’s log file, increase the
- If you do not encounter these messages in the
- We recommend that you reevaluate these values whenever changes in load occur or whenever the number of domains that the system hosts changes.