Setting up automatic Smart Search indexing
From Joomla! Documentation
Although the Smart Search index is automatically kept up-to-date whenever content items are amended, there are some circumstances where you need to re-run the indexer. You can do this manually using the Index toolbar button in the Manage Indexed Content screen, however if you need to re-index content automatically then it is also possible to run the indexer as a command-line application. This makes it particularly convenient to run the indexer from a cron job.
The Smart Search CLI application is located in the cli directory in your site's root directory (that is, the same directory as your configuration.php file). In this directory you will find the finder_indexer.php file. Simply enter this command to run the indexer:
In Joomla 4:
php -d memory_limit=512M joomla.php finder:index
Typical output from the command-line indexer looks like this:
Smart Search INDEXER ============================ Starting Indexer Setting up Finder plugins Setup 154 items in 0.094 seconds. * Processed batch 1 in 0.213 seconds. * Processed batch 2 in 0.182 seconds. * Processed batch 3 in 0.177 seconds. * Processed batch 4 in 0.009 seconds. Total Processing Time: 0.676 seconds.
Purging Before Indexing
Ordinarily, running the indexer will do an incremental update of the index. That is, it will only update the index for those content items that have changed since the index was last updated. However, if you need to completely clear all the existing index entries before completely rebuilding the index, then you need to do a "purge and then index" operation. To do that you can add the --purge argument to the command line, like this
php finder_indexer.php --purge
Note that this will attempt to preserve any static filters you may have set up, whereas clicking on the "Purge" toolbar button in the Administrator will not preserve your static filters.
Setting Up a cron Job
Whilst the specifics are beyond the scope of this article, in general you will merely have to enter the above command into the cron job manager and specify the time or times on which the job is to be run. You will probably need to include the full path to the indexer. For example, like this
Out of Memory Issues
If your site has particularly complex indexing requirements it is possible that the standard memory allocation will not be sufficient for the indexer to run to completion. You can increase the memory allocated to the command-line indexer using an extra parameter on the command-line, like this:
php -d memory_limit=256M finder_indexer.php
Replace the 256M with whatever is appropriate for your circumstances.
The command-line indexer uses the same parameters as the indexer on the Manage Indexed Content screen. You can change the parameters using the Options toolbar button on that screen. Note that both the Indexer Batch Size and Memory Table Limit fields affect the amount of memory used by the indexer.