19 lines
926 B
Plaintext
19 lines
926 B
Plaintext
Allows several servers to appear as one to the outside and automatically
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detects servers that are down and distributes clients among the
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available servers. This gives high availability and scalable
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performance.
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The load balancing algorithm keeps track of clients and will try to send
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them back to the server they visited the last time. The client table has
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a number of slots (2048 by default). When the table is full, the least
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recently used one will be thrown out to make room for the new one. When
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pen detects that a server is unavailable, it scans for another starting
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with the server after the most recently used one. That way we get load
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balancing and "fair" failover for free.
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A side-effect of the load-balancing is that several logfiles are
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produced, and all accesses seem to come from the load balancer. The
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program mergelogs solves this problem by merging pen's log file with the
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ones produced by the web servers.
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