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Problem(Abstract) |
This technote clarifies information in the Load Balancer
Administration Guide concerning how traffic is handled when all servers
are down on a cluster and the interaction of the following script files:
managerAlert, managerClear, serverUp, serverDown. |
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Cause |
By design, rather than dropping all traffic, Load Balancer
continues to attempt to route traffic to servers marked down, in case a
server comes back online and responds to the request,. |
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Resolving the
problem |
If all servers on a cluster are marked down (either by the
user or by the advisors), the managerAlert (if configured) is executed,
and Load Balancer attempts to route traffic to the servers using a
round-robin technique. The serverDown script does not execute when the
last server in the cluster is detected as offline.
By design, Load Balancer attempts to continue to route the traffic in
case a server comes back online and responds to the request. If Load
Balance instead dropped all traffic, the client would receive no
response.
When Load Balancer detects that the first server of a cluster is back
online, the managerClear script (if configured) is executed, but the
serverUp script (if configured) is not executed until an additional server
is brought back online.
For more information on these script files, refer to the "Using scripts
to generate an alert or record server failure" section in the Load
Balancer Administration Guide.
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Cross Reference information |
Segment |
Product |
Component |
Platform |
Version |
Edition |
Application Servers |
WebSphere Edge Server |
Load Balancer |
AIX, Linux, Solaris, Windows 2000 |
Edge Server 2.0 GA, Edge Server 2.0 NLV, Edge Server 2.0 PTF1, Edge
Server 2.0.x |
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Application Servers |
Runtimes for Java Technology |
Java SDK |
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Historical Number |
1845845 |
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