In the Web GUI under “Server Monitoring”, I see two figures that seem relevant to memory usage.
“Wowza Heap” and “Total Memory.”
Is there a description available on what these mean?
Thank you.
Hello there.
Wowza heap is what Java reserves for Wowza’s use. Total memory is what is available on the machine.
The higher the heap setting (in Tuning) the lower available memory will be. Within the reserved heap, there is available and used. So the heap might be taking up a lot of memory from the machine but not using much of it necessarily.
You can read more about this here:
Regards,
Salvadore
Hi,
The Wowza Heap is the amount of Memory Wowza is using out of the total it has available as defined in the Java Heap Size.
If the Java Heap Size is 10,000 MB and you’re using 50% as shown in the Wowza Heap, you’ll be using 5,000 MB.
You’ll need more memory for the server if you’re often in the high 80% range when viewing the Wowza Heap and doesn’t drop or you start seeing “out of memory” messages in the log file.
Regards,
Jason
Salvadore,
Thank you for the description on memory.
I have read the mentioned page, and would appreciate a few more words on remaining questions.
Is there a way to view the amount of used and unused memory among the reserved heap?
All above questions arose in the course of trying to determine when our server should need more RAM.
Is there a rule of thumb on deciding the amount of RAM?
Our Wowza4 server is currently running on a Win x64/64bit Java with 4GB of RAM.
It is dedicated for Wowza other than CPU hungry VNC used during remote access.
Live streaming only, no VOD.
As it is for a closed service, stream & clients counts are predictable.
Graphs show the heap increasing to roughly 2GB, then dropping to 100MB over a 10 minutes cycle.
Perhaps this is the GC doing its job, and we should be fine with even half the amount RAM, but hoping to find evidence to back up up this guess.
Thank you.
Thank you, Jason.
As of now the “Wowza Heap” gradually increases to about 2GB, but then drops down to 400MB or less every 10 minutes or so, so I assume we are still quite good to go with 4GB of RAM.
Hi,
Yes those numbers look OK. As Jason says if your used heap is constantly high then this may indicate that you need to increase the heap size or that something is consuming it, in which case it would need to be investigated.
Regarding your initial query, you may want to look at a tool such as jstat which you can use to query the JVM and see in detail how much heap memory is being used etc. You can also use tools such as Jconsole to query Java usage and present it in a graphical format. We have this article which shows how to use this with Wowza.
Paul