DVR -- Degenerative performance over time

Channels DVR Server
#1

Hello,

I'm running Channels DVR on a Synology DS218+ with a 4TB drive. The 218+ is dedicated to Channels -- I do not use it to run anything else. In addition, I do not regularly reboot the box or otherwise fool with any of the processes (there should be no need to do such things anyway).

As Channels runs, I notice that it slowly consumes the available system memory. Once free memory gets to below about 40%, things start going bad. CPU utilization gets pegged, the web server becomes sluggish, commercial skipping takes longer to run, guide downloads take hours to perform, etc. Eventually, clients start failing to load (web-based and Fire TV), and scheduled recordings are missed. A reboot sets things straight.

There's nothing in the logs that indicates that anything is wrong. Is there anything else that I should look at? Some (hopefully) relevant screenshots are attached. One thing to note -- the activity showing ch6051 being watched is stale. The stream was shut down approximately 20 minutes prior to the screenshot being taken. Don't know what's up with that...

channelsdvr_1
channelsdvr_1.jpg1131×461 73.4 KB
channelsdvr_2
channelsdvr_2.jpg1045×690 287 KB

#2

I've seen this on our DS218+ once or twice. I suspect there's a memory leak here or there. Whack and restart the Channels DVR server and it returns to normal.

#3

My installation of Channels uses very little RAM, so I'm not quite sure what you're seeing there.

However, if your NAS is only running Channels and you're concerned about exhausting resources on the device, you may want to stop the other services running on it. For instance, the top view seemed to show both AudioStation and Synology Drive running, the last which is quite resource intensive on the device.

You may want to go through the installed packages and remove everything that isn't necessary, and then disable the un-removable packages.

#4

Strange. Can you click-and-hold the Update button to see if this still happens?

Is the FireTV set to Home Quality: Original ?

#5

tmm1 -- I had to reboot the 218+ (performance got too bad). I'll leave it running on the 2/26 build to see when things start getting bad.

The hung stream activity in the screenshot was a local web browser (Chrome). All of my local devices (all the Fire TV's) are set to original quality.

FYI -- upon rebooting, available memory was at 78%. Also, performance appears to get particularly bad when retrieving guide updates (9AM local time). I have Locast, 2 TVE providers, and a HDHR as sources. In low memory situations, the guide DL/processing stretches to well over an hour.

#6

Screenshot_2020-03-11%20DVR%20--%20Degenerative%20performance%20over%20time
Is your Synology time zone set correctly?

Screenshot_2020-03-11%20Synology%20DiskStation
Screenshot_2020-03-11 Synology DiskStation.png509×534 14.7 KB

#7

Funny you ask -- it wasn't, but it is now.

I got the 218+ in December, and it was set up as GMT-5 (don't recall how I arrived at that). Anyway, with the time change this past weekend, I noticed it when I SSH'ed into the box. I've since fixed it to be ET.

Anyway, it turns out that Channels actually continued to work properly, even though the system time was wrong. I'm guessing that they use UTC across their guides and recording jobs, etc.

#9

Is this easy to reproduce? If so, the next time this happens if you can go to http://DVR:8089/debug/stack and email the output to [email protected] we should be able to figure it out.

#10

Done. Let me know if I can provide anything else.