[kamailio/kamailio] ratelimit module not working properly when FEEDBACK algorithm is used (#871)
30 Nov
2016
30 Nov
'16
1:45 p.m.
I'm currently using version 4.4.2 and I am came across an issue while using the
ratelimit module with the FEEDBACK algorithm.
Checking the ratelimit.c to see how the cpu load value is calculated I saw that the module
parses only the line corresponding to the overall CPU usage in the "/proc/stat"
file.
First, the module calculates the amount of CPU that is idle, in percentage.
But, when the module is going to calculate the percentage of the overall CPU usage, it
first divides the idle value obtained previously by the number of CPU cores, and then
subtracts this value from 1.
The mistake here seems to be the division by the number of CPU cores, because the overall
porcentage retrieved from the /proc/stat file is already in the range from 0-100,
regardless of the number of CPU cores
--
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/kamailio/kamailio/issues/871
30 Nov
30 Nov
3:36 p.m.
The fix I purpose is commited at pull request #873.
--
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/kamailio/kamailio/issues/871#issuecomment-263904800
4:48 p.m.
The mistake here seems to be the division by the
number of CPU cores, because the overall porcentage retrieved from the /proc/stat file is
already in the range from 0-100, regardless of the number of CPU cores
From `man proc`
The amount of time, measured in units of USER_HZ
(1/100ths of a second on most architectures, use sysconf(_SC_CLK_TCK) to obtain the right
value), that the system spent in various states:
So *not* a percentage
```
/proc/stat
kernel/system statistics. Varies with architecture. Common entries include:
cpu 3357 0 4313 1362393
The amount of time, measured in units of USER_HZ (1/100ths of a second on most
architectures, use sysconf(_SC_CLK_TCK) to obtain the right value), that the system spent
in various states:
user
(1) Time spent in user mode.
nice
(2) Time spent in user mode with low priority (nice).
system
(3) Time spent in system mode.
idle
(4) Time spent in the idle task. This value should be USER_HZ times
the second entry in the /proc/uptime pseudo-file.
iowait (since Linux 2.5.41)
(5) Time waiting for I/O to complete.
irq (since Linux 2.6.0-test4)
(6) Time servicing interrupts.
softirq (since Linux 2.6.0-test4)
(7) Time servicing softirqs.
steal (since Linux 2.6.11)
(8) Stolen time, which is the time spent in other operating systems
when running in a virtualized environment
guest (since Linux 2.6.24)
(9) Time spent running a virtual CPU for guest operating systems under
the control of the Linux kernel.
guest_nice (since Linux 2.6.33)
(10) Time spent running a niced guest (virtual CPU for guest operating
systems under the control of the Linux kernel).
page 5741 1808
The number of pages the system paged in and the number that were paged out
(from disk).
swap 1 0
The number of swap pages that have been brought in and out.
intr 1462898 This line shows counts of interrupts serviced since boot time,
for each of the possible system interrupts. The first column is the total of all
interrupts serviced including unnumbered architecture specific interrupts; each subsequent
column is the total for that particular numbered interrupt. Unnumbered interrupts are not
shown, only summed into the total.
disk_io: (2,0):(31,30,5764,1,2) (3,0):...
(major,disk_idx):(noinfo, read_io_ops, blks_read, write_io_ops, blks_written)
(Linux 2.4 only)
ctxt 115315
The number of context switches that the system underwent.
btime 769041601
boot time, in seconds since the Epoch, 1970-01-01 00:00:00 +0000 (UTC).
processes 86031
Number of forks since boot.
procs_running 6
Number of processes in runnable state. (Linux 2.5.45 onward.)
procs_blocked 2
Number of processes blocked waiting for I/O to complete. (Linux 2.5.45
onward.)
```
--
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/kamailio/kamailio/issues/871#issuecomment-263926477
5:05 p.m.
Yes, the data retrieved from /proc/stat is indeed a unit of hertz, but, when you take the
total time spent and divide by the amount of time the CPU is idle, you have a percentage
of the CPU's idle time. (exactaly as the ratelimit module does).
The problem is, this percentage is being divided by the number of CPU cores, but it should
not.
--
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/kamailio/kamailio/issues/871#issuecomment-263931518
13 Dec
13 Dec
8:15 a.m.
Related PR was pushed a while ago.
--
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/kamailio/kamailio/issues/871#issuecomment-266674106
8:15 a.m.
Closed #871.
--
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/kamailio/kamailio/issues/871#event-891618141
2710
days inactive
2723
days old
5 comments
3 participants
participants (3)
-
Daniel-Constantin Mierla -
GUILHERME CESAR PILON
-
Victor Seva