glassfish load balancer principle of operation
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27-06-2021 - |
Вопрос
I have configured cluster with two instances on glassfish 3.1.1 and iPlanet Web Server as a load-balancer (on the same machine). For test application provided with glassfish everything works ok (and this application has session replication enabled).
But when I try to make my own application working following situation takes place: it responds when I send requests on ports of a particular instances (that is 28080 and 28081), but when I try to send request through load balancer (port 81) I get error 404. My application has not session replication enabled yet, but it can just make a connection and create two other sessions for each instance. I would like to get similar effect with load balancer.
So I would like to determine:
- Is session replication strongly required to load balancer works fine?
- Does anyone know any other reasons of this error?
Message from iPlanet log:
[23/Aug/2012:05:44:16] failure ( 4120) myHost: for host 127.0.0.1 trying to GET /myApp/login.jsp, service-j2ee reports: PWC6117: File "c:/webserver7/https-myHost/docs/myApp/login.jsp" not found
Additional conclusions:
(81 - http-listener port on iPlanet)
When I send GET http://localhost:81/testApp
then loadbalancer passes it to glassfish and returns correct site. But when I try the same with my test application, GET http://localhost:81/myApp
then iPlanet looks for this site in its own resources (docs directory as in log above)
fragment of myHost-obj.conf:
<Object name="default">
AuthTrans fn="match-browser" browser="*MSIE*" ssl-unclean-shutdown="true"
NameTrans fn="name-trans-passthrough" name="lbplugin" config-file="C:/WebServer7/https-myHost/config/loadbalancer.xml"
NameTrans fn="assign-name" name="perf" from="/.perf"
NameTrans fn="ntrans-j2ee" name="j2ee"
NameTrans fn="pfx2dir" from="/mc-icons" dir="C:/WebServer7/lib/icons" name="es-internal"
PathCheck fn="uri-clean"
PathCheck fn="check-acl" acl="default"
PathCheck fn="find-pathinfo"
PathCheck fn="find-index-j2ee"
PathCheck fn="find-index" index-names="index.html,home.html,index.jsp"
ObjectType fn="type-j2ee"
ObjectType fn="type-by-extension"
ObjectType fn="force-type" type="text/plain"
Service method="(GET|HEAD)" type="magnus-internal/directory" fn="index-common"
Service method="(GET|HEAD|POST)" type="*~magnus-internal/*" fn="send-file"
Service method="TRACE" fn="service-trace"
Error fn="error-j2ee"
AddLog fn="flex-log"
</Object>
Решение
First, if you are running the Load Balancer plugin, then you may have a support contract (a GlassFish license is required before you put the plugin into production). If so, calling support is a good option.
To answer your first question, session replication is not required for the Load Balancer to work.
As a shameless plug, I have a 5-part youtube series on setting this up. You can skip the videos on downloading and installing and go straight to setup/configuration/testing. Based on what you describe, I suspect the issue isn't the plugin itself, but the loadbalancer.xml configuration. Look at loadbalancer.xml and see if myApp is configured.
Hope this helps.