In this case NOC stands for Network Operations Center, and calling it that might be a BIT misleading, because you don't have a tremendous amount of control you could exert over the network from this single node. This mechanism also doesn't allow for monitoring switches (although there is no reason why it shouldn't work with Linux routers.)
What you do have is a central point that aggregates ALL the available info about EVERY z/Linux host in your config. This allows you to do some pretty neat profiling stuff, comparing loads on like-purposed hosts etc... The limits to what you could do in terms of aggregating and publishing (and logging) of kernel information are limited only by the extents of the info available in /proc. To the best of my knowledge virtually everything the kernel knows is available under the /proc directory. If you run apache on the host you can very easily display a summary of the health and well-being of all your penguins, either on your intranet for management types to see how great your utilization is, or on the Internet for your hosting or web-service clients to look at your availability info. All without SNMP. This monitor node could also be a distinct machine like a 386 running debian, and it can monitor any other Linux machine on your network. But of course, you'll get the best performance if the whole mess is on one mainframe installation, preferably under z/VM though distinct LPARS don't present any problem either. I did make one mistake in my earlier post, all your kernels need the 9p module, not just the one doing the aggregation. In fact this is exactly what /proc is FOR, or at any rate, this is the purpose of the system that these concepts were adopted from. Plan 9 even includes a debugger called acid which got all its info through the /proc interface, allowing you to remotely attach to and debug a running process. Dtrace cannot do that, afaik. There exists an acid port as part of the Plan 9 From Userspace project but it is not complete. It does, however have very interesting capabilities already please see the man page online (http://swtch.com/plan9port/man/man1/acid.html). I have posted about Plan 9 From Userspace in the past, it also goes by the name plan9port and contains a variety of novel unix-style tools including a graphical editor in the spirit of ed (called sam) as well as unicode aware troff, grep (the plan 9 grep is more like egrep, fair warning) sed and many others, as well as some new tools designed to work with the 9p network filesystem. If nothing else some of these tools provide much cleaner, lighter-weight equivalents to their GNU counterparts, and will build under pretty much any C compiler. (Read: DOES NOT REQUIRE automake, autoconf, gmake, or gcc.) To find out a bit more about these concepts in general you can read about it on Wikipedia under Plan 9 From Bell Labs (http://en.wikipedia.org/wiki/Plan_9_from_Bell_Labs). For more info on plan9port see Russ Cox's Plan 9 From Userspace website (http://swtch.com/plan9port). For specific info on how to use v9fs see their documentation page (http://git.kernel.org/?p=linux/kernel/git/ericvh/v9fs.git;a=blob_plain;f=Documentation/filesystems/9p.txt;hb=HEAD). The v9fs project was begun by Ron Minnich and Maya Gokhale of Los Alamos. Their involvement in the project was funded under two distinct DARPA contracts. The kernel module is distributed with the vanilla kernel from kernel.org, and is not flagged experimental. I have looked for the date when it was added to the mainline kernel but have not found it. Erik Johnson P.S. I agree that Dtrace syntax (and all other white-space-significant language) is fugly. If people would refrain from using whitespace to delimit code then varying indentation style would be irrelevant, since the proper incantation to BSD's indent will render any C, C++, Java, Perl, or other sanely constructed language file into an indentation style that a particular programmer finds optimally readable. If I run indent on a Python program it breaks. This seems to me a bit of a throw-back to me. On Fri, Mar 27, 2009 at 9:55 AM, Dave Jones <[email protected]> wrote: > Eric, could you expand on your idea here a bit more? What's a Linux NOC? > > Thanks. > > Erik N Johnson wrote: >> >> In an attempt to bring things back on topic for Scott, and everybody >> else who is supposed to keep e-mail work related (sorry guys!) I would >> like to point out a major feature of Linux that people seem to remain >> unaware of. In Linux you can get virtually any piece of kernel >> information from the vfs through the novel /proc filesystem. I have >> discussed this and other ports from the Plan 9 From Bell Labs >> operating system to Linux (especially the 9p kernel module.) No other >> operating system has, to the best of my knowledge, any attempt at >> these features. What's really great about this is that for a z/Linux >> farm you can easily use 9p to create a single virtual host whch has a >> /mnt all full of: >> /mnt >> /host1/proc >> /host2/proc >> ... >> /hostN/proc >> >> then a perl (or shell or python) script ( or ANY filesystem-aware >> program, which is pretty open-ended) can easily do: >> >> foreach host in hosts { >> displayRelevantInfo( /mnt/host/proc); >> } >> >> where hosts is the full set of Linux guests. >> >> Voila, pure Linux NOC w/out nasty, insecure SNMP. With HiperSocket >> this is going to be VERY fast. It DOES require a custom kernel on the >> virtual host which is serving as the NOC, as 9p is a kernel module. >> >> This is the type of thing that a GPL-compatible license brings to your OS. >> >> Erik Johnson >> >> ---------------------------------------------------------------------- >> For LINUX-390 subscribe / signoff / archive access instructions, >> send email to [email protected] with the message: INFO LINUX-390 or >> visit >> http://www.marist.edu/htbin/wlvindex?LINUX-390 > > -- > Dave Jones > V/Soft > www.vsoft-software.com > Houston, TX > 281.578.7544 > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
