Re: Query Cache and DataDomain Snap Shot Cache

From: Andrus Adamchik (andru..bjectstyle.org)
Date: Wed Sep 23 2009 - 09:51:34 EDT

  • Next message: Malcolm Edgar: "Re: Query Cache and DataDomain Snap Shot Cache"

    You are correct - flushing query cache groups across the cluster with
    JGroups (or something else) is a low overhead way to propagate
    updates. My usual setup is to have post-update/remove/persist
    listeners generate a distributed event with a cache group appropriate
    for the object being saved. This allows to define flush granularity at
    any level desired.

    I don't have JGroups config specifically restricted to localhost,
    however I haven't seen any problems with network flooding with mine.
    Unless you also have some security considerations, you can use
    something like that:

    UDP(mcast_addr=231.12.21.132;mcast_port=45569;ip_ttl=4;tos=0;mcast_send_buf_size=150000;mcast_recv_buf_size=80000;bind_port=20000;port_range=500):PING(timeout=2000;num_initial_members=3):MERGE2(min_interval=5000;max_interval=10000):FD_SOCK:VERIFY_SUSPECT(timeout=1500):pbcast.NAKACK(gc_lag=50;retransmit_timeout=300,600,1200,2400,4800):UNICAST(timeout=300,600,1200,2400):pbcast.STABLE(desired_avg_gossip=20000):FRAG(frag_size=8096):pbcast.GMS(join_timeout=5000;shun=false;print_local_addr=true)

    Andrus

    On Sep 23, 2009, at 4:34 PM, Malcolm Edgar wrote:
    > Hi All,
    > I am looking to improve the performance of a set of web applications
    > running. We have one application which is used mainly for
    > adminsitration/configuration and a number of public facing web
    > applications
    > which can have a high load.
    >
    > I have been experimenting with OSCache but the problem I see is that
    > the
    > query cache and the object cache are not unified, so I sometimes have
    > situations where the objects from the caches are not consistent.
    > While the
    > query cache can timeout, the object cache doesn't, so if another web
    > application makes an update the object cache in this application is
    > not
    > updated.
    >
    > I presume the answer to this problem is using JGroups, if so does
    > anyone
    > have a configuration where its constrained to localhost. I don't
    > really want
    > to be broadcasting notification messages across the network.
    >
    > regards Malcolm Edgar



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