I have a simple pool created with 4 Linux web servers in it. (running version 10.2.1) Two of the webservers are physical machines, and two are virtual. I have selected round-robin as the load-balancing method, disabled priority group activation, and the ratios for each member in the group is set to 1, connection limit for each member is set to zero. Whenever I look at the statistics, the physical servers are getting about 6 to 8 times the connections of the virtual machines. The physical machines do have more memory then the virtual machines, but I've verified the virtual machines have plenty of free memory available, and the load average is roughly the same across all the servers. So I have no idea why the Virtual Machines have such a low connection count as compared to the physical machines. I've checked the apache configs and made sure the number of servers, threads, etc are set to be the same across all machines. Any clues or things I should check for to verify the round-robin is working as expected, or is this a bug or expected behavior? Thanks,

Would anything in here apply? http://support.f5.com/kb/en-us/solutions/public/10000/400/sol10430.html

I've checked that documentation. The only iRule being applied is selectiveSNAT, which maps SNAT IPs. Straight Round robin for the pool. The only thing that I see that could come into play is the selection of Type of Performance under the Virtual Server Properties. But the documentation doesn't indicate this will result in any preference being given to members based on response time.

OK. I assume you are getting enough connections to make the statistics valid. What statistics are you actually looking at? Are these borne out by similar stats on the servers?

Could you post the VIP and Pool configuration from the bigip.conf file?

Ok, see below, pretty straightforward. I also tried changing the profile in the Virtual definition to Standard, made no difference.. pool pool_live.sample.com_40001 { monitor all slow_icmp members { 10.48.2.37:40001 {} 10.48.2.38:40001 {} 10.48.2.39:40001 {} 10.48.2.42:40001 {} } } pool pool_live.sample.com_http { monitor all slow_icmp members { 10.48.2.37:http {} 10.48.2.38:http {} 10.48.2.39:http {} 10.48.2.42:http {} } } virtual live.sample.com_http { pool pool_live.sample.com_http destination 10.48.254.79:http ip protocol tcp rules SelectiveSNAT profiles fastL4 {} } virtual live.sample.com_https { pool pool_live.sample.com_40001 destination 10.48.254.79:https ip protocol tcp rules SelectiveSNAT profiles fastL4 {} }

Pool round-robin load balancing not balanced

21 Replies

Taylor77_133376

Nimbostratus

Sep 10, 2013

Sys::Hardware
Chassis Fan Status
  Index  Status  Fan Speed(rpm)
  1      up      9926
  2      up      10546
  3      up      9926

Chassis Information
  Maximum MAC Count  2
  Registration Key   -

Chassis Power Supply Status
  Index  Status
  1      up
  2      up

Chassis Temperature Status
  Index  Temp(degC)  Location
  1      36          Air Inlet

CPU Status
  Index  Temp(degC)  Fan Speed(rpm)
  1      46          10546

Hardware Version Information
  Name        cn0
  Type        crypto
  Model       Cavium NITROX-PX
  Parameters  --          --
              version     CNPx-MC-SSL-MAIN-0013

  Name        cpld
  Type        pic
  Model       F5 cpld
  Parameters  --          --
              version     0x13

  Name        cpus
  Type        base-board
  Model       Intel(R) Pentium(R) Dual  CPU  E2160  @ 1.80GHz
  Parameters  --          --
              cache size  1024 KB
              cores       2  (cores/cpu:2)
              cpu MHz     1800.108


Platform
  Name           BIG-IP 1600
  BIOS Revision  F5 Platform: C102 OBJ-0332-01 BIOS (build: 130) Date: 12/28/09


System Information
  Type                       C102

Joe_M
Nimbostratus
Sep 10, 2013
What is the uptime on the device?
Taylor77_133376
Nimbostratus
Sep 10, 2013
228 days
Joe_M
Nimbostratus
Sep 10, 2013
There are some known issues with uptime. Non with round robin that I am familiar with but doing a reboot wouldn't hurt. Also, at some point, I would definitely recommend upgrading to 10.2.4 with the latest Hotfix.

What_Lies_Bene1
Cirrostratus
Sep 10, 2013
OK, thanks, so it's a CMP system. Are we talking about a low number of connections or not?
What_Lies_Bene1
Cirrostratus
Sep 10, 2013
OK, so the system distributes connections across the two TMMs running (one per core) so you'd be down to 75/100 per TMM. Even if one started the Pool RR allocation at Pool Member 1 and the other at 3 you should still end up with a fairly even spread I'd say. That being the case I'm a bit stuck.
Kevin_Davies_40
Nacreous
Sep 11, 2013
Are the pool members 37/38/39/42 all separate Linux servers? Some on hardware and some vmware?

If you watch a single connection serverside with tcpdump to the hardware version and do the same with a connection the vmware server is the behaviour of the connection the same?
- Taylor77_133376
  Nimbostratus
  Sep 23, 2013
  Yes, seperate linux servers, 2 physical, 2 virtual. TCPdump looks about the same. One thing I notice, is from the f5, pings to the physical boxes take about half the time (averaged over several pings) as compared to pings to the virtual servers.

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Pool round-robin load balancing not balanced

21 Replies

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