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>
diff --git a/src/cfgparse.c b/src/cfgparse.c
index b3435ef..a85bbed 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -4392,9 +4392,9 @@
else if (!strcmp(args[cur_arg], "weight")) {
int w;
w = atol(args[cur_arg + 1]);
- if (w < 0 || w > 256) {
- Alert("parsing [%s:%d] : weight of server %s is not within 0 and 256 (%d).\n",
- file, linenum, newsrv->id, w);
+ if (w < 0 || w > SRV_UWGHT_MAX) {
+ Alert("parsing [%s:%d] : weight of server %s is not within 0 and %d (%d).\n",
+ file, linenum, newsrv->id, SRV_UWGHT_MAX, w);
err_code |= ERR_ALERT | ERR_FATAL;
goto out;
}