The archive plugin is a commercial Graylog feature that can be installed in addition to the Graylog open source server.
Please see the Graylog Enterprise setup page for details on how to install the Archive plugin.
The archive plugin can be configured via the Graylog web interface and does not need any changes in the Graylog server configuration file.
In the web interface menu navigate to “System/Archives” for the configuration.
The “Configuration” section on the page shows the current configuration values. You can change the configuration by pressing “Update configuration”.
There are several configuration options to configure the archive plugin.
|Archive Path||Directory on the master node where the archive files will be stored.|
|Max Segment Size||Maximum size (in bytes) of archive segment files.|
|Compression Type||Compression type that will be used to compress the archives.|
|Restore index batch size||Elasticsearch batch size when restoring archive files.|
The archived indices will be stored in the Archive Path directory. This directory needs to be writable for the Graylog server process so the files can be stored.
Only the master node needs access to the Archive Path directory because the archiving process runs on the master node.
We recommend to put the Archive Path directory onto a separate disk or partition to avoid any negative impact on the message processing should the archiving fill up the disk.
Max Segment Size¶
When archiving an index, the archive job writes the data into segments. The Max Segment Size setting sets the size limit for each of these data segments.
This allows control over the file size of the segment files to make it possible to process them with tools which have a size limit for files.
Once the size limit is reached, a new segment file will be started.
/path/to/archive/ graylog_201/ archive-metadata.json archive-segment-0.gz archive-segment-1.gz archive-segment-2.gz
Archives will be compressed with gzip by default. This option can be changed to use a different compression type.
The selected compression type has a big impact on the time it takes to archive an index. Gzip for example is pretty slow but has a great compression rate. Snappy and LZ4 are way faster but the archives will be bigger.
Here is a comparison between the available compression algorithms with test data.
|Type||Index Size||Archive Size||Duration|
|gzip||1 GB||134 MB||15 minutes, 23 seconds|
|Snappy||1 GB||291 MB||2 minutes, 31 seconds|
|LZ4||1 GB||266 MB||2 minutes, 25 seconds|
Results with your data may vary! Make sure to test the different compression types to find the one that is best for your data.
The current implementation of LZ4 is not compatible with the LZ4 CLI tools, thus decompressing the LZ4 archives outside of Graylog is currently not possible.
Restore Index Batch Size¶
This setting controls the batch size for re-indexing archive data into
Elasticsearch. When set to
1000, the restore job will re-index the
archived data in document batches of 1000.
You can use this setting to control the speed of the restore process and also how much load it will generate on the Elasticsearch cluster. The higher the batch size, the faster the restore will progress and the more load will be put on your Elasticsearch cluster in addition to the normal message processing.
Make sure to tune this carefully to avoid any negative impact on your message indexing throughput and search speed!
Graylog is using configurable index retention strategies to delete old indices. By default indices can be closed or deleted if you have more than the configured limit.
The archive plugin offers a new index retention strategy that you can configure to automatically archive an index before closing or deleting it.
Index retention strategies can be configured in the system menu under “System/Indices”. Click “Update configuration” to change the index rotation and retention strategies.
As with the regular index retention strategies, you can configure a max number of Elasticsearch indices. Once there are more indices than the configured limit, the oldest ones will be archived to the Archive Path and then closed or deleted. You can also decide to not do anything (NONE) after archiving an index. In that case no cleanup of old indices will happen and you have to take care of that yourself!