Re: [javagroups-users] FD protocol w/ two hosts

[Bela B. <be...@ya...>]

Can you set TCP.bind_addr as well ? Should only matter when you have 
multiple NICs

Les Hazlewood wrote:

> Bela,
>
> Thanks very much for the response.  I spent most of my last day or so 
> playing with configurations after reading your reply.
>
> But I'm still not getting any luck.
>
> Please try this from two different machines:
>
> java -cp jgroups.jar org.jgroups.demos.NotificationBusDemo -bus_name 
> test-group -props 
> "TCP(start_port=7800):TCPPING(initial_hosts=192.168.0.1[7800],192.168.0.2[7900];num_initial_members=2;up_thread=true;down_thread=true):MERGE2(min_interval=5000;max_interval=10000):FD:VERIFY_SUSPECT(timeout=1500):pbcast.NAKACK(down_thread=true;up_thread=true;gc_lag=100;retransmit_timeout=3000):pbcast.GMS(join_timeout=5000;join_retry_timeout=2000;shun=false;print_local_addr=false)"
>
> After they've both started and you receive membership notification on 
> both, unplug the network cable from one of the machines.  Wait about 
> 10 to 20 seconds and then plug it back in.
>
> On my boxes, they're not finding each other after plugging back in.  I 
> tried both the MERGE2 and MERGEFAST protocols to no avail.  I tried 
> switching the initial_hosts order as well, and still no luck.
>
> Am I doing something wrong?  Are my configuration settings for the 
> stack incorrect?
>
> Any insight would be graciously received.
>
> Regards,
>
> Les
>
>
> -----Original Message-----
> From: Bela Ban [mailto:be...@ya...]
> Sent: Mon 6/21/2004 12:52 PM
> To: Les Hazlewood
> Cc: jav...@li...
> Subject: Re: [javagroups-users] FD protocol w/ two hosts
>
> Hi Les,
>
> simple: add the MERGE2 protocol to your stack, e.g.:
>
>  ...
>  <PING timeout="2000" num_initial_members="3"/>
>  <MERGE2 max_interval="10000" min_interval="5000"/>
>  <FD timeout="2000" max_tries="3" shun="true"/>
>    ...
>
>
> You may also want to experiment with MERGEFAST.
>
> Les Hazlewood wrote:
>
> >Hiya folks,
> >
> >First off, I'd like to say this is my first time using JGroups 
> directly (i.e. not as an 'oem' feature, like w/ JBoss), and I'm very 
> happy with its architecture and simplicity.  Cheers to Bela and the 
> rest of you working on this great product.
> >
> >Ok, here's my setup/issue:
> >
> >I'll be deploying in a WAN environment, and in my LAN and simulated 
> WAN tests, I have two servers.  They both use the NotificationBus 
> under the hood to take care of group membership notification and 
> messaging.  They both need Failure Detection to know of each other's 
> existence.
> >
> >FD works great with both UDP/PING multicast as well as TCP/TCPPING.  
> Each server can detect when there is a legitimate crash or the 
> opposing member explicitly leaves the group.
> >
> >The one issue I have is the following:
> >
> >Server A and B have both started and both joined the group and are 
> both aware of each other.
> >
> >To simulate a WAN link going down or being disrupted, I unplug the 
> network cable from one of the machines, and they both correctly detect 
> the "failure" of the other and do their necessary exclusion processing.
> >
> >When I plug in the network cable 10 to 20 seconds after unplugging it 
> to simulate network reconnection, the servers can't "find" each other 
> unless I manually restart the NotificationBus on one of them.
> >
> >After reading the JavaDoc for FD, I realized this is because pinging 
> behavior stops after the group membership count drops below 2.  This 
> means that upon a detected member leaving the group, it won't ever try 
> to ping/communicate with that member again until the remote member 
> explicitly indicates it is back online.
> >
> >This means FD can't resolve the network conditions I just 
> described/tested.
> >
> >Now, I understand what I want isn't just failure detection.  What I 
> want is more of a true heartbeat mechanism.
> >
> >Is there a way I can get the functionality I desire with some other 
> form of FD or other JGroups Protocol?
> >
> >I tested out FD_SOCK as well, but that doesn't tell me when a machine 
> fails fast enough. Excluding the VERIFY_SUSPECT time, I require 
> knowing within 5 seconds of a machine failure.  Because FD_SOCK relies 
> on socket timeouts (2 - 10/12 minutes), that isn't sufficient for my 
> requirements.
> >
> >If JGroups doesn't provide this functionality already, is there a way 
> I can insert my own Protocol in the stack?
> >
> >My assumption would be that each protocol corresponds to a name of a 
> class (e.g. FD or VERIFY_SUSPECT or pbcast.FD) relative to a base 
> default package (org.jgroups.protocols).  If I wanted to create my own 
> protocol in the stack, can I specify the fully qualified class name in 
> the stack string?  Would that work?
> >
> >Example:
> >
> >"UDP(.....):PING(.....):com.my.company.pkg.HEARTBEAT(.....):..." etc.
> >
> >Naturally, I would only want to do this if JGroups doesn't support 
> what I'm looking for.
> >
> >Does anyone have any feedback for me?  Anyone?  
> Bueller....Bueller....? ;)
> >
> >Regards, and thanks for dealing with the long email.
> >
> >Les Hazlewood
> >ers=
> >
>
> --
> Bela Ban
> Lead JGroups / JBossCache
>
>
>
>
>

-- 
Bela Ban
Lead JGroups / JBossCache