Update on collectl
Last summer I announced that I had released a performance monitoring tool called collectl and just wanted to let people know I've since significantly improved the website at http://collectl.sourceforge.net/ to include examples, a block diagram and even included a couple of pages on some interesting kernel problems it helped identify, though they've since been addressed. Perhaps one of the more interesting ones is that not too long ago, and I'm really not sure when it actually got fixed, it was impossible to accurately measure network traffic at 1 second intervals and worse, you'd periodically see double the actual rate reported. Try it out on an older kernel and see for yourself! However, since collectl can monitor at subsecond intervals you could monitor those older kernels at 0.9765 seconds and see accurate data. Rather than me try to explain it, take a look at http://collectl.sourceforge.net/NetworkStats.html to read more. I think a couple of other features I may not have said enough about is monitoring Infiniband and Lustre performance, for which I don't believe there are any good tools available. You can get IB data from asking the switch, but you can't easily get it from the local system. There is actually a wealth of information Lustre provides but no good tools to mine it. Now there is. With collectl you can see a second-by-second (or any other interval you prefer) snapshot of just what is happening to these key resources and can even watch the load on cpu, memory and network at the same time. If you prefer, and most people do, just run collectl as a service and it will maintain a set of compressed rolling logs containing 10 second samples (all customizable) and do it all at <0.1% of system overhead. Enough rambling already. Download it and see for yourselves... -mark -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Update on collectl
Last summer I announced that I had released a performance monitoring tool called collectl and just wanted to let people know I've since significantly improved the website at http://collectl.sourceforge.net/ to include examples, a block diagram and even included a couple of pages on some interesting kernel problems it helped identify, though they've since been addressed. Perhaps one of the more interesting ones is that not too long ago, and I'm really not sure when it actually got fixed, it was impossible to accurately measure network traffic at 1 second intervals and worse, you'd periodically see double the actual rate reported. Try it out on an older kernel and see for yourself! However, since collectl can monitor at subsecond intervals you could monitor those older kernels at 0.9765 seconds and see accurate data. Rather than me try to explain it, take a look at http://collectl.sourceforge.net/NetworkStats.html to read more. I think a couple of other features I may not have said enough about is monitoring Infiniband and Lustre performance, for which I don't believe there are any good tools available. You can get IB data from asking the switch, but you can't easily get it from the local system. There is actually a wealth of information Lustre provides but no good tools to mine it. Now there is. With collectl you can see a second-by-second (or any other interval you prefer) snapshot of just what is happening to these key resources and can even watch the load on cpu, memory and network at the same time. If you prefer, and most people do, just run collectl as a service and it will maintain a set of compressed rolling logs containing 10 second samples (all customizable) and do it all at 0.1% of system overhead. Enough rambling already. Download it and see for yourselves... -mark -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
