RPP Performance troubleshooting
When do performance problems occur?
- If you have too many (over 10 000) posts on a relatively small hosting plan
- If the configuration is incorrect
- If the hosting provider throttles the database traffic (like WP Engine does on some hosting plans)
- If too many concurrent plugins are installed – this is a very frequent issue nowadays
- If the Relatad Posts Pro plugin malfunctions for yet unknown reasons
Since I can't influence your database size nor your hosting provider, I will help you fine-tuning the plugin configuration for the maximum possible performance based on your server setup.
If you however have a relatively small data set and your hosting provider is trustworthy and you still experience major performance issues, I recommend opening a support ticket if this article won't help.
Having super relevant results costs more (harder) database operations, which may result in slower plugin response. The plugin tries to create a query as optimal as possible, but please don't expect google-like speed and relevance. WordPress and your hosting provider servers have their limits, which is far below anything like Google or Yahoo.
Confirming performance issues
As of plugin version 1.1 there is a performance tracker available, which will help you tracking the query times and the memory usage. Once you feel that there is a definitive slowdown, you should absolutely check the performance tracker sub menu, to see how bad the problem is.
What run time and memory values are acceptable?
There are no exact values, they are highly dependent on your server setup and database size. But you probably should not get an average runtime above 1 second on small databases with an average hosting plan. The peak memory usage may highly vary, as it's extremely hard to measure correctly.
Before You start
It's advised to confirm that no other plugin/theme is conflicting with Related Posts Pro, which might save you some time.
- Try to disable all other plugins temporary but Related Posts Pro and check if there is any change in the performance
- Try to switch the theme to the default temporary, and check if there is any change in performance
If you find that by disabling other plugins highly increases the performance, try to activate them on one by one to see which one might be conflicting. Then you either don't use the conflicting plugin, or open a support ticket – then I can try to find and fix the possible conflict.
Improving performance with configuration
The correct plugin configuration can highly impact it's performance. This is especially true for sites with big data sets.
Choosing Relevance Fields
The more fields are active, the slower the plugin gets. This is not much noticeable on small databases, but it definitely is on a big site. If you have many items, I suggest you turn off the Content and the Excerpt relevance on the Relevance Options -> Content Options panel.
Decreasing the keyword count
This is another configuration, that has a great performance impact. On the Relevance Options -> Keyword Options panel you can select how the plugin should choose the relevance keywords based on the current post content. By default it selects 10 keywords at maximum, but in some cases that might be too much. Try to decrease the Keywords maximum count option to 2 or 3 at first and check how it impacts the performance.
Limiting the results number
Limiting how many results you expect on the front end can slightly improve the plugin performance. Lower numbers are usually much better. Go to the General Options panel, and the first option is the Max items count. Try to decrease it below 6 and check how it affects the page loading time.
Make sure you haven't disabled cache
Caching the results is turned on by default, so repetitive page loading should be much much faster from the initial page load. Make sure that this is enabled on the Advanced Option panel.
You can even increase the Cache Expiration timeout, if your content does not change that frequently. Use values 86400 for a day, 604800 for a week.
If nothing helps
If none of these tips help you affecting the plugin performance, then feel free to open a support ticket with proper temporary login and FTP details to your test environment. In the ticket description please also include which steps you tried from this guide. I'll check and debug the plugin to see what causes the delay on the output.