Hi,

I would like to do a long term monitoring project over the next week but I want to minimize the amount of data stored in memory. So I want to use the Auto Save feature.

One hour seems like a good time interval to do my saving and I’ve set the sample interval to 2.5 seconds. So I set the Max samples to keep in memory at 1500. (3600 sec / 2.5 sec per sample = 1440. Giving me 60 samples for wiggle room for write latencies and things like that.)

1) From what I’ve read it appears that auto save will NOT clear the samples from memory. Is this correct?

2) I noticed that if I set the file name to something static (e.g. X.pp2) the data appears to be appended to it. Exactly what is appended, everything that is memory or just the samples that have not previously been saved (assuming that auto save does not clear memory)? Will those extra 60 samples I pointed out above cause any problems i.e. will thay be duplicated?

3) After the monitoring session is complete, and I double click on the auto save file what is read back into memory? What I mean is, in question 3 I think the appended data will include some overlaps so if there are overlaps does PP handle this when the dataset is read in?

4) I notice that when I open an auto save file the “Max samples to keep in memory” setting is set to whatever I’ve set it at previously. So, if number of samples saved is greater than this number what happens when the file is opened (or does it really matter)?


Thanks!
-Kevin

1) You are correct. Auto-saving will save the data in memory, but doesn't change what's in memory in any way.

2) When auto-save saves, it takes the data in memory and saves it into the file. If that file already exists, it is overwritten. The contents of any file already on disk are not taken into account - the new file is just written over top of it (with the contents of what's in memory at that exact moment).

3) When you reload any of this data in to memory, your reloaded data will be the exact copy of what was in memory at the time of save.

4) If you load, the "Max samples to keep in memory" is disregarded until the next sample is collected. As long as you're not collecting data, this setting isn't an issue. As soon as you collect any data, however, any old data in memory will be discarded if your samples in memory exceeds the setting.

Now, let's get a bit more to the *guts* of what you're trying to accomplish.

If your save file name is set to $host $date $hour (and has a $hour factor in it), then you can set your max samples to include in memory to something as low as an hour and not lose any data. This isn't what I recommend, however.

I would recommend keeping a day's worth of data in memory. At 2.5 seconds, this is 34560 samples - or roughly 1.3 megabytes of collected data. It may be that you don't have this much free memory - in which case you might set it to something lower.

You want to keep enough data in memory so you can see a pretty good overview of what was happening - without having to load each file individually. I like to have 48 hours in memory at a time - so I'd actually set mine to 75000 or so (actually, I use 2.5 second and run mine at 200000 - but that's more than most people need). I'm not sure the constraints you're going to run in to with memory, but 1.5 megs is a drop in the bucket these days <G>.

Why do you want more data in memory? Well, you can only graph what you have in memory, so if you only have an hour worth of data in memory, then your time graphs can only show an hour's worth of data - which is useful, but isn't enough data to show trending.

Note that 1500 samples is only about 60K of data - pretty much nothing on a modern system. I'd strongly recommend having more data in memory at a time.

Feel free to follow up with any additional questions / recommendations.

- Pete

I've tried almost every settings just like you did guys. But I still get memory overloaded after a few weeks of monitoring.

Here's my setup.

I have 3 pings running at the same time on the same machine.
All three have the same settings:
#Sample to include: 5
Trace interval: 1 second
Max. Samples in memory: 86400 (24 hours)
Autosave : every 4 hours
Filename: $host $date $Hour00

After two weeks the computers memory was at 300 Mo while physical memory is 128Mo.
When I end Ping plotter's instances memory drops to 150Mo.
I then restart ping plotter with the latest file saved, and memory raises up to 160Mo.

So I don't think this ping plotter is doing good usage of this memory. There is something wrong I guess.

Thanks.

Pascal Bellerose
It Site Manager
Cascades, Fine Papers Group inc., Fibres Breakey division

Hi, Pascal.

We see a pretty solid memory footprint here over time, but it's possible that your network conditions may be causing PingPlotter some issues that we're not seeing.

Can you send us a .pp2 save file with a days worth of data in it? We can then use this to replay in our environment and see if we can isolate what's causing this memory growth.

Send the data to support@pingplotter.com, and reference that you're sending it in response to this forum post.

Thanks for letting us know you're having problems with this.

- Pete