Sharepoint - Search processes consuming a lot of memory

There are some information about this behaviour. See here and here.

You can change e.G. the Performance Levels for your crawls.

Powershell Cmdlet:

Get-SPEnterpriseSearchService | Set-SPEnterpriseSearchService –PerformanceLevel "PartlyReduced"

For the setting to take effect do an IISReset or restart the Search Service in Central Admin

Performance Level Explained:

Reduced:

Total number of threads = number of processors, Max Threads/host = number of processors

PartlyReduced:

Total number of threads = 4 times the number of processors , Max Threads/host = 16 times the number of processors

Maximum:

Total number of threads = 4 times the number of processors , Max Threads/host = 16 times the number of processors (threads are created at HIGH priority)

Change noderunner.exe:

You can also edit the noderunner.exe config file located at:

C:\Program Files\Microsoft Office Servers\15.0\Search\Runtime\1.0\noderunner.exe

And set a value for <nodeRunnerSettings memoryLimitMegabytes="0" />

The zero means "unlimited" here. The only thing to do is to set to the amount of RAM you'd like to set as a limit for each noderunner.exe processes.

NOTE: Be aware, these settings might make your crawling processes slower.

Hope this will help a little.

8 GB is way below the minimum for a standalone SharePoint server in production.

See this Technet Article.

After you "solve" this issue you will face many more until you add RAM and resources.