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Jean-Frederic Clere closed MODCLUSTER-606.
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Documentation Error - Chapter 10 - Time decay formulas
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Key: MODCLUSTER-606
URL:
https://issues.redhat.com/browse/MODCLUSTER-606
Project: mod_cluster
Issue Type: Bug
Components: Documentation & Demos
Affects Versions: 1.2.13.Final, 1.3.7.Final
Reporter: Leandro Quiroga
Assignee: Jean-Frederic Clere
Priority: Minor
Labels: documentation
Original Estimate: 1 hour
Remaining Estimate: 1 hour
In chapter 10 (
http://docs.jboss.org/mod_cluster/1.3.0/html_single/#java.load), it says:
The DynamicLoadBalanceFactorProvider applies a time decay function to the loads returned
by each metric. The aggregate load, with respect to previous load values, can be expressed
by the following formula:
L = (L ~0~ + L ~1~/D + L ~2~/D ^2^ + L ~3~/D ^3^ + ... + L ~H~/D ^H^) * (1 + D + D ^2^ +
D ^3^ + ... D ^H^)
... or more concisely as:
L = (∑^H^~i=0~ L ~i~/D ^i^) * (∑^H^~i=0~ D ^i^)
... where D = decayFactor, and H = history.
But both formulas are wrong.
It should says:
The DynamicLoadBalanceFactorProvider applies a time decay function to the loads returned
by each metric. The aggregate load, with respect to previous load values, can be expressed
by the following formula:
L = (L ~0~*/D ^0^* + L ~1~/D *^1^* + L ~2~/D ^2^ + L ~3~/D ^3^ + ... + L ~H~/D ^H^) */
(1/D ^0^ + 1/D ^1^ + 1/D ^2^ + 1/D ^3^ + ... 1/D ^H^)*
... or more concisely as:
L = (∑^H^~i=0~ L ~i~/D ^i^) */* (∑^H^~i=0~ *1/* D ^i^)
... where D = decayFactor, and H = history.