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Diffstat (limited to 'net/pen/DESCR')
| -rw-r--r-- | net/pen/DESCR | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/net/pen/DESCR b/net/pen/DESCR new file mode 100644 index 00000000000..866200b66fa --- /dev/null +++ b/net/pen/DESCR @@ -0,0 +1,20 @@ +Pen is a load balancer for "simple" tcp based protocols such as http or +smtp. It allows several servers to appear as one to the outside and +automatically detects servers that are down and distributes clients among +the available servers. This gives high availability and scalable +performance. + + The load balancing algorithm keeps track of clients and will try to +send them back to the server they visited the last time. The client +table has a number of slots (default 2048, settable through command-line +arguments). When the table is full, the least recently used one will +be thrown out to make room for the new one. + + This is superior to a simple round-robin algorithm, which sends a client +that connects repeatedly to different servers. Doing so breaks +applications that maintain state between connections in the server, +including most modern web applications. + + When pen detects that a server is unavailable, it scans for another +starting with the server after the most recently used one. That way +we get load balancing and "fair" failover for free. |