docker stats shows that the cpu usage to be very high. But top command out shows that 88.3% cpu is not being used. Inside the container is a java service httpthrift service.
docker stats :
CONTAINER CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS
8a0488xxxx5 540.9% 41.99 GiB / 44 GiB 95.43% 0 B / 0 B 0 B / 35.2 MB 286
top output :
top - 07:56:58 up 2 days, 22:29, 0 users, load average: 2.88, 3.01, 3.05
Tasks: 13 total, 1 running, 12 sleeping, 0 stopped, 0 zombie
%Cpu(s): 8.2 us, 2.7 sy, 0.0 ni, 88.3 id, 0.0 wa, 0.0 hi, 0.9 si, 0.0 st
KiB Mem: 65959920 total, 47983628 used, 17976292 free, 357632 buffers
KiB Swap: 7999484 total, 0 used, 7999484 free. 2788868 cached Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
8823 root 20 0 58.950g 0.041t 21080 S 540.9 66.5 16716:32 java
How to reduce the cpu usage and bring it under 100%?
According to the top man page:
When operating in Solaris mode (`I' toggled Off), a task's cpu usage will be divided by the total number of CPUs. After issuing this command, you'll be told the new state of this toggle.
So by pressing the key I when using top in interactive mode, you will switch to the Solaris mode and the CPU usage will be divided by the total number of CPUs (or cores).
P.S.: This option is not available on all versions of top.
Related
cpu:8
memory:64G
when use docker swarm to deploy application, already limit cpu and memory
docker service update java --reserved-cpu 2 --limit-cpu 2 --limit-memory 4G --reserve-memory 4G
use top to check server,
top - 11:09:26 up 889 days, 19:31, 16 users, load average: 72.50, 78.28, 55.54
Tasks: 271 total, 2 running, 183 sleeping, 0 stopped, 0 zombie
%Cpu(s): 36.7 us, 7.2 sy, 0.0 ni, 52.4 id, 0.0 wa, 0.0 hi, 3.7 si, 0.0 st
KiB Mem : 65916324 total, 27546636 free, 8884904 used, 29484784 buff/cache
KiB Swap: 0 total, 0 free, 0 used. 56442876 avail Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
15566 root 20 0 12.563g 2.871g 17580 S 199.0 4.6 42:06.92 java
45076 root 20 0 19.018g 337692 16680 S 167.2 0.5 0:07.38 java
14692 root 20 0 1941688 122152 50868 S 4.0 0.2 617:42.71 dockerd
have not other application, why load average run so high
could someone help to check it，thx
I have CentOS 6.8, Cassandra 3.9, 32 GB RAM. When I start Cassandra and once it is started, it starts consuming the memory and start adding up 'Cached' memory value when I start querying from CQLSH or Apache Spark and in this process, very less memory remain for other processing like cron execution.
Here are some details from my system
free -m
total used free shared buffers cached
Mem: 32240 32003 237 0 41 24010
-/+ buffers/cache: 7950 24290
Swap: 2047 25 2022
And here is the output of top -M command
top - 08:54:39 up 5 days, 16:24, 4 users, load average: 1.22, 1.20, 1.29
Tasks: 205 total, 2 running, 203 sleeping, 0 stopped, 0 zombie
Cpu(s): 3.5%us, 1.2%sy, 19.8%ni, 75.3%id, 0.1%wa, 0.1%hi, 0.0%si, 0.0%st
Mem: 31.485G total, 31.271G used, 219.410M free, 42.289M buffers
Swap: 2047.996M total, 25.867M used, 2022.129M free, 23.461G cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
14313 cassandr 20 0 595g 28g 22g S 144.5 91.3 300:56.34 java
You can see only 220 MB is left and 23.46 is cached.
My question is how to configure Cassandra so that it can use 'cached' memory to certain value and leave more RAM available for other processes.
Thanks in advance.
In linux in general cached memory as your 23g is just really fine. This memory is used as filesystem cache and so on - not by cassandra itself. Linux systems tend to use all available memory.
This helps to speed up your system in many ways to prevent disk reads.
You can still use the cached memory - just start processes and use your ram, the kernel will free it immediatly.
You can set the sizes in cassandra-env.sh under conf folder. This article should help. http://docs.datastax.com/en/cassandra/3.0/cassandra/operations/opsTuneJVM.html
The problem
One of my Python Redis clients fails with the following exception:
redis.exceptions.ResponseError: MISCONF Redis is configured to save RDB snapshots, but is currently not able to persist on disk. Commands that may modify the data set are disabled. Please check Redis logs for details about the error.
I have checked the redis machine, and it seems to be out of memory:
free
total used free shared buffers cached
Mem: 3952 3656 295 0 1 9
-/+ buffers/cache: 3645 306
Swap: 0 0 0
top
top - 15:35:03 up 14:09, 1 user, load average: 0.06, 0.17, 0.16
Tasks: 114 total, 2 running, 112 sleeping, 0 stopped, 0 zombie
%Cpu(s): 0.2 us, 0.3 sy, 0.0 ni, 99.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.2 st
KiB Mem: 4046852 total, 3746772 used, 300080 free, 1668 buffers
KiB Swap: 0 total, 0 used, 0 free. 11364 cached Mem
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
1102 root 20 0 3678836 3.485g 736 S 1.3 90.3 10:12.53 redis-server
1332 ubuntu 20 0 41196 3096 972 S 0.0 0.1 0:00.12 zsh
676 root 20 0 10216 2292 0 S 0.0 0.1 0:00.03 dhclient
850 syslog 20 0 255836 2288 124 S 0.0 0.1 0:00.39 rsyslogd
I am using a few dozens Redis DBs in a single Redis instance. Each DB is denoted by numeric ids given to redis-cli, e.g.:
$ redis-cli -n 80
127.0.0.1:6379[80]>
How do I know how much memory does each DB consume, and what are the largest keys in each DB?
How do I know how much memory does each DB consume, and what are the largest keys in each DB?
You CANNOT get the used memory for each DB. With INFO command, you can only get the totally used memory for Redis instance. Redis records the newly allocated memory size, each time it dynamically allocates some memory. However, it doesn't do such record for each DB. Also, it doesn't have any record for the largest keys.
Normally, you should config your Redis instance with the maxmemory and maxmemory-policy (i.e. eviction policy when the maxmemory is reached).
You can write some sh-script like to this (show element count in each DB):
#!/bin/bash
max_db=501
i=0
while [ $i -lt $max_db ]
do
echo "db_nubner: $i"
redis-cli -n $i dbsize
i=$((i+1))
done
Example output:
db_nubner: 0
(integer) 71
db_nubner: 1
(integer) 0
db_nubner: 2
(integer) 1
db_nubner: 3
(integer) 1
db_nubner: 4
(integer) 0
db_nubner: 5
(integer) 1
db_nubner: 6
(integer) 28
db_nubner: 7
(integer) 1
I know that we can have a one database with large key, but anyway, in some cases this script can help.
I am trying to figure out what is wrong with my Debian server - I am getting warnings of having not enough free memory - top (as you can see below) is saying that 1.8G is consumed, but I am unable to find which application is responsible for it. There is only Tomcat running, which consumes, according to top, ~25 % and so 530m. But There is more than 1 GB left, which I am unable to find!
Tasks: 54 total, 1 running, 53 sleeping, 0 stopped, 0 zombie
Cpu(s):100.0%us, 0.0%sy, 0.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 2150400k total, 1877728k used, 272672k free, 0k buffers
Swap: 0k total, 0k used, 0k free, 0k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
3271 root 18 0 1559m 530m 12m S 0 25.2 1:44.31 java
1568 mysql 15 0 270m 71m 7332 S 0 3.4 0:50.79 mysqld
(Full top output here)
Linux systems always try to use as much ram as available for various functions like caching of executables our even just page reads from disk. That's what you bought your fast RAM for after all.
You can find out more about your system by doing a
cat /proc/meminfo
More info in this helpful blog post
If you find out a lot is used in cache then you don't have to worry about the system.if individual processes warn you about memory issues then you'll have to check their settings for any memory limiting settings. Many server processes have those, like php or java based processes.
Questions of this nature are also probably more at home at https://serverfault.com/
As i see, your 'Free' command returned NO swap space
Swap: 0k total, 0k used, 0k free, 0k cached
either there is no swap partition available
this swap space is not mounted
one can manual make a swapfile
and mount this file as becoming the active swap
howto make swap
To test your real usage
reboot the machine and
test the used amount
retest after 1 hour
some processes are memory hoggs
like apache or ntop
refer:
check memory
display sorted
memory usage
Here is my problem:
top - 11:32:47 up 22:20, 2 users, load average: 0.03, 0.72, 1.27
Tasks: 112 total, 1 running, 110 sleeping, 1 stopped, 0 zombie
Cpu(s): 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 8193844k total, 7508292k used, 685552k free, 80636k buffers
Swap: 2102456k total, 15472k used, 2086984k free, 7070220k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
28555 root 20 0 57424 38m 1492 S 0 0.5 0:06.38 bash
28900 root 20 0 39488 7732 3176 T 0 0.1 0:03.12 python
28553 root 20 0 72132 5052 2600 S 0 0.1 0:00.22 sshd
28859 root 20 0 70588 3424 2584 S 0 0.0 0:00.06 sshd
29404 root 20 0 70448 3320 2600 S 0 0.0 0:00.06 sshd
28863 root 20 0 42624 2188 1472 S 0 0.0 0:00.02 sftp-server
29406 root 20 0 19176 1984 1424 S 0 0.0 0:00.00 bash
2854 root 20 0 115m 1760 488 S 0 0.0 5:37.02 rsyslogd
29410 root 20 0 19064 1400 1016 R 0 0.0 0:05.14 top
3111 ntp 20 0 22484 604 460 S 0 0.0 10:26.79 ntpd
3134 proftpd 20 0 64344 452 280 S 0 0.0 6:29.16 proftpd
2892 root 20 0 49168 356 232 S 0 0.0 0:31.58 sshd
1 root 20 0 27388 284 132 S 0 0.0 0:01.38 init
3121 root 20 0 4308 248 172 S 0 0.0 0:16.48 mdadm
As you can see 7.5 GB of memory is used, but there is no process that use it.
How it can be, and how to fix this?
Thanks for answer.
www.linuxatemyram.com
It's too good of a site to ruin by copy/pasting the entire contents here.
in order to see all process you can use that command:
ps aux
and then try to sort with different filters
ps faux
Hope that helps.
If your system starts using the swap file - then you have high memory load. Depends on the file system, programs that you use - linux system may allocate all of your system memory - but that doesn't mean that they are using it.
Lots of ubuntu and debian servers that we use have free memory 32 or 64 mb but don't use swap.
I'm not Linux-gure however, so please someone to correct me if I'm wrong :)
I don't have a Linux box handy to experiment, but it looks like you can sort top's output with interactive commands, so you could bring the biggest memory users to the top. Check the man page and experiment.
Update: In the version of top I have (procps 3.2.7), you can hit "<" and ">" to change the field it's sorting by. Doesn't actually say what field it is, you have to look at how the display is changing. It's not hard once you experiment a little.
However, Arrowmaster's point (that it's probably being used for cache) is a better answer. Use "free" to see how much is being used.
I had a similar problem. I was running Raspbian on a Pi B+ with a TP-Link USB Wireless LAN stick connected. The stick caused a problem which resulted in nearly all memory being consumed on system start (around 430 of 445 MB). Just like in your case, the running processes did not consume that much memory. When I removed the stick and rebooted everything was fine, just 50 MB memory consumption.