packets being  sent to and from  the database and application servers are fully utilized.

Posted on 2009-02-20
Last Modified: 2013-11-12
looking for answer to above without having to hook up a traffic analyzer. Oracle Server has option to increase buffer size from 4096k to 32k. Was wondering if increasing size would speed communication between servers and maximize payload on gigethernet link . I guess I would need to somehow measure buffer status during transfer and how often it becomes empty. Open for suggestions. I know max gigeth packet size on ethernet is 1500 bytes and cisco supports a jumbo frame as well. I am network literate but not server literate. I do not have direct access to servers. Thanks and looking forward to reply.
Question by:chardavis5044
    1 Comment
    LVL 28

    Accepted Solution

    Using Jumbo frames is something that really needs to be done on ALL devices on a subnet, including hosts, switches, etc. -- because if a packet was sent to a device that didn't understand the packet, it would choke.  As such, you're usually in for a major redesign, involving all devices, to jump to these larger frames.

    As for the question of whether it will help you or not, this is another issue.  A network analyzer will be the only real way to tell how effectively things are working.  You can mirror a switch port to the analyzer and look at it from there.  For a database communications sequence like this, look for the percentage of "continuation" packets (i.e. those that do not have the PUSH bit set) compared to the overall packet count.  A percentage of 50% (in one direction) means that the database is using roughly two packets to send each data block (around 3K).  A higher percentage would indicate the chance that you CAN effectively use larger blocks.

    Also, you may wish to note that the Oracle data block size and the network block size may NOT be related.  Note that TCP is a streaming technology.  This means that if Oracle builds a 20K data block to send to a client, the TCP stack will break it up into 15 or so packets of data -- and then stream them very rapidly across the wire without waiting for an ACK on every packet.  This will provide a performance gain on even a standard size Ethernet packet.  

    Obviously, if you had enabled Jumbo frames, that same 20K block would only take three (9K) packets, so you would find even better performance, since the overhead (CPU and network interframe gap) on both sides of the link would be reduced by a factor or 7 or so.

    Featured Post

    What Security Threats Are You Missing?

    Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

    Join & Write a Comment

    Network ports are the threads that hold network communication together. They are an essential part of networking that can be easily ignore or misunderstood, my goals is to show those who don't have a strong network foundation how network ports opera…
    Creating an OSPF network that automatically (dynamically) reroutes network traffic over other connections to prevent network downtime.
    After creating this article (, I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…
    After creating this article (, I decided to make a video (no audio) to show you how to configure the routers and run some trace routes and pings between the 7 sites…

    728 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    16 Experts available now in Live!

    Get 1:1 Help Now