Help Needed With Poor Performance in Microsoft NLB

Discussion in 'Clustering' started by adoughe, Jan 16, 2014.

  1. adoughe

    adoughe Guest

    **************
    Overview
    **************
    There are two web servers in our web farm, WEB1 and WEB2.
    Each web server has four NICs:
    a management (mgt)NIC
    two NICs configured for Microsoft NLB
    one NIC disabled
    Two clusters are serviced by these servers, WEBFARM1 and WEBFARM2, and all NICs on these servers are in our DMZ subnet.

    We have a serious performance issue when either of these web farm servers connect to the reporting server. A non-load-balanced development web server can get a report in about 30 seconds but when using the web servers in the web farm the same report takes 3-4 minutes.

    **************
    WEB1
    Dell PowerEdge 1950
    Windows Server 2008 R2 Standard
    4GB RAM

    NIC 1: 192.168.123.7 ( mgt IP address )( Broadcom BCM5708C NetXtreme II GigE )
    192.168.123.1 ( gateway )
    NIC 2: NLB for WEBFARM2 ( Intel(R) Gigabit ET Dual Port Server Adapter)
    192.168.123.157
    192.168.123.156 ( cluster IP address for WEBFARM2 )
    192.168.123.1 ( gateway )
    NIC 3: NLB for WEBFARM1 ( Broadcom BCM5708C NetXtreme II GigE )
    192.168.123.152
    192.168.123.151 ( cluster IP address for WEBFARM1 )
    192.168.123.1 ( gateway )
    NIC 4: <disabled> ( Intel(R) Gigabit ET Dual Port Server Adapter)


    **************
    WEB2
    Dell PowerEdge 1950
    Windows Server 2008 R2 Standard
    4GB RAM

    NIC 1: 192.168.123.8 ( mgt IP address )( Broadcom BCM5708C NetXtreme II GigE )
    192.168.123.1 ( gateway )
    NIC 2: NLB for WEBFARM2 ( Intel(R) Gigabit ET Dual Port Server Adapter )
    192.168.123.158
    192.168.123.156 ( cluster IP address for WEBFARM2 )
    192.168.123.1 ( gateway )
    NIC 3: NLB for WEBFARM1 ( Broadcom BCM5708C NetXtreme II GigE )
    192.168.123.153
    192.168.123.151 ( cluster IP address for WEBFARM1 )
    192.168.123.1 ( gateway )
    NIC 4: <disabled> ( Intel(R) Gigabit ET Dual Port Server Adapter )

    The web servers connect to a SSRS server at 172.16.xxx.120, our LAN.

    **************
    REQUIREMENTS
    **************

    WEBFARM1 and WEBFARM2 must serve HTTPS (443) data to both the Internet and the Internal LAN

    Websites on both WEB1 and WEB2 must be able to be isolated and sites accessed by LAN via NLB Addresses of:
    192.168.123.152, 192.168.123.153, 192.168.123.157, and 192.168.123.158
    We do this via IIS Host Headers so we can troubleshoot individual sites on individual servers.

    WEB1 and WEB2 must access SSRS server (172.16.xxx.120) via HTTP (80) to usereporting services

    We would like the HTTP (80) Traffic from WEB1 and WEB2 to go to the SSRS Server via the management NICS if possible, WEB1 – 192.168.123.7 and WEB2 – 192.168.123.8 respectively depending on what server is making the request to SSRS on the LAN

    **************
    Issue
    **************

    Poor performance in running reports from WEBFARM1 and WEBFARM2 as well as poor performance running reports while WEB1 and WEB2 are isolated from the cluster

    Reports take 3 to 4 minutes when they should take around 30 seconds

    We tested with Wireshark with the test web server “stopped” in the clusters so that we see isolated controlled traffic only from server WEB1 to the SSRS server.

    **
    ** Test 1
    **

    WEB1 server simply “stopped” in the clusters, no change to any NIC configurations

    IP Addresses used
    Vast majority of traffic was to and from 192.168.123.152, the NIC IP address for WEBFARM1 even though we were testing WEBFARM2
    Very minimal traffic also seen to and from the cluster IP address for WEBFARM2

    Performance
    Degraded performance, test report takes eight times or longer to retrieve than expected
    Excessive TCP retransmissions, TCP Fast Retransmissions and TCP Out-of-Order packets
    More IP addresses in play than expected

    **
    ** Test 2
    **

    WEB1 server “stopped” in the clusters and the gateway IP address removed from WEBFARM1

    IP addresses used
    Traffic to and from only cluster IP address for WEBFARM2

    Performance
    Normal performance, test report completes in the expected time
    No problem packets, no retransmissions or anything at all. A clean packet capture

    **************
    Question
    **************

    How can we reconfigure these servers to meet the requirements shown above that doesn't result in a degradation in performance? Is three NICs with NLB on two of them a supported or recommended configuration? We would appreciate a verbose explanation of any problems seen in our configuration as well as a clear explanation of what we need to do with hyperlinks to supporting articles if possible. We are hoping someone knows exactly what our problem is and can specifically point it out to us and give us a direction in correcting it along with any helpful links. Thanks!
     
    adoughe, Jan 16, 2014
    #1
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.