If you are collecting the inventory file semi-dynamically, why not randomize the order while you are collecting the hosts?
On Sunday, October 5, 2014 8:53:10 PM UTC+2, Eric Wedaa wrote: > > > Changing the setting to random and the fork value to 40 gives me a > reasonable chance that all 40 forks will be more or less equally > distributed. With more than 40 blades, it's a good bet only one fork per > blade. Of course, being random, I could someday get all 40 forks going to > one blade. It's not that the blade is already at 100% CPU, it's that > hitting a single blade with 40 updates at the same time will not only > flatline my cpu, but the ethernet sockets for the same blade as well. And > on some of my blades, the system may try and move LPARs to different blades > to re-equalize the load, which just then makes it take even longer. > > This is a semi-common option, at least in the network scanning tools I > have used. I was hoping it would already be here and I just wasn't seeing > it. > > For instance, > > Nmap 6.47SVN ( http://nmap.org ) > Usage: nmap [Scan Type(s)] [Options] {target specification} > TARGET SPECIFICATION: > -iR <num hosts>: Choose random targets > > > And for Nessus > http://static.tenable.com/documentation/nessus_5.0_user_guide.pdf page > 11 > > Avoid Sequential Scans > > By default, Nessus scans a list of IP addresses in sequential order. If > checked, Nessus > will scan the list of hosts in a random order. This is typically useful > in helping to > distribute the network traffic directed at a particular subnet during > large scans > > > > We have to be careful when we scan our Z series boxes for instance with > Nessus. Thank goodness for random host selection. > > This is a scalability issue as far as I am concerned. > > >>>Ericw > > On Sunday, October 5, 2014 2:23:20 PM UTC-4, Michael DeHaan wrote: >> >> There's no such setting. >> >> However, I don't understand why changing the order wouldn't smakc your >> *other* blade, so this question seems orthogonal. >> >> Sounds like you need to take it out of rotation if it's already nearing >> 100% CPU, such as using our load balancing modules. >> >> >> >> On Sun, Oct 5, 2014 at 1:24 PM, Eric Wedaa <[email protected]> wrote: >> >>> How do I shuffle/randomize long lists of hosts? That is, without >>> writing an executable hosts file that randomizes them and then spits them >>> out, and then dealing with all the groupings and variables and other >>> wonderfulness that I can include in the hosts file? >>> >>> My inventory file is collected semi-dynamically and comprises long lists >>> of servers that are all running on the same blade on a long list of >>> blades. I run upto 40 servers per blade, and I have about a 80 blades (or >>> more). The FIRST time I run an "update bash" (for instance) I'll wind up >>> hitting all of one blade first, effectively flat-lineing it. If I can >>> shuffle my hosts list, I can have a larger fork/serial value and won't >>> flatline my blades and I can shorten my effective runtime. >>> >>> I was hoping for a "--shuffle-hosts" variable but I couldn't find it. >>> >>> >>>Ericw >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Ansible Project" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/ansible-project/679fde26-6b71-49ab-a836-f0806d545d3c%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/ansible-project/679fde26-6b71-49ab-a836-f0806d545d3c%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- You received this message because you are subscribed to the Google Groups "Ansible Project" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/ansible-project/ea17be2f-be9c-44b9-a2d5-307b0c4b9149%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
