haproxy/doc
Godbach a34bdc0ea4 BUG/MEDIUM: server: set the macro for server's max weight SRV_UWGHT_MAX to SRV_UWGHT_RANGE
The max weight of server is 256 now, but SRV_UWGHT_MAX is still 255. As a result,
FWRR will not work well when server's weight is 256. The description is as below:

There are some macros related to server's weight in include/types/server.h:
    #define SRV_UWGHT_RANGE 256
    #define SRV_UWGHT_MAX   (SRV_UWGHT_RANGE - 1)
    #define SRV_EWGHT_MAX   (SRV_UWGHT_MAX   * BE_WEIGHT_SCALE)

Since weight of server can be reach to 256 and BE_WEIGHT_SCALE equals to 16,
the max eweight of server should be 256*16 = 4096, it will exceed SRV_EWGHT_MAX
which equals to SRV_UWGHT_MAX*BE_WEIGHT_SCALE = 255*16 = 4080. When a server
with weight 256 is insterted into FWRR tree during initialization, the key value
of this server should be SRV_EWGHT_MAX - s->eweight = 4080 - 4096 = -16 which
is closed to UINT_MAX in unsigned type, so the server with highest weight will
be not elected as the first server to process request.

In addition, it is a better choice to compare with SRV_UWGHT_MAX than a magic
number 256 while doing check for the weight. The max number of servers for
round-robin algorithm is also updated.

Signed-off-by: Godbach <nylzhaowei@gmail.com>
2013-07-22 09:29:34 +02:00
..
design-thoughts DOC: add a diagram to explain how circular buffers work 2012-04-30 11:57:00 +02:00
internals DOC: update document describing relations between internal entities 2012-10-26 20:40:13 +02:00
acl.fig [DOC] add diagrams of queuing and future ACL design 2009-02-22 16:46:38 +01:00
architecture.txt MINOR: patch for minor typo (ressources/resources) 2012-03-21 07:54:41 +01:00
close-options.txt [DOC] add a few old and uncommitted docs 2011-09-05 01:04:44 +02:00
coding-style.txt DOC: add a coding-style file 2011-12-30 17:33:27 +01:00
configuration.txt BUG/MEDIUM: server: set the macro for server's max weight SRV_UWGHT_MAX to SRV_UWGHT_RANGE 2013-07-22 09:29:34 +02:00
cookie-options.txt [DOC] add a few old and uncommitted docs 2011-09-05 01:04:44 +02:00
gpl.txt [LICENSE] licensing clarifications 2006-06-15 21:48:13 +02:00
haproxy-en.txt MEDIUM: New cli option -Ds for systemd compatibility 2013-02-13 10:47:49 +01:00
haproxy-fr.txt MEDIUM: New cli option -Ds for systemd compatibility 2013-02-13 10:47:49 +01:00
haproxy.1 MEDIUM: New cli option -Ds for systemd compatibility 2013-02-13 10:47:49 +01:00
lgpl.txt [LICENSE] licensing clarifications 2006-06-15 21:48:13 +02:00
proxy-protocol.txt DOC: update the PROXY protocol spec to support v2 2012-11-19 11:27:29 +01:00
queuing.fig [DOC] add diagrams of queuing and future ACL design 2009-02-22 16:46:38 +01:00