pihole Kubernetes

pihole web Interface no accessable on Kubernets , php-crashing

php -i -> works 

php-cgi -I -> error bus error en crash

do you have huge pages enabled on your linux system, check  (this message is enabled):

cat /sys/kernel/mm/redhat_transparent_hugepage/enabled

[always] madvise never

The problem with Kubbernetes and php-cgi huge pages needs assigned to the container or php-cgi crashes, as I have mayastor running in Kubernetes I can't disable hughe pages so to assign it add :


you need to set a hugepage limit on the container, here in my setup I did 512Mi

resources:

          limits:

            cpu: "1"

            hugepages-2Mi: 512Mi

            memory: 2Gi

          requests:

            cpu: 100m

            memory: 128Mi




Background stuff from : 

How to configure huge pages

clyso@compute-21:~$ grep Hugepagesize /proc/meminfo

Hugepagesize: 2048 kB

clyso@compute-21:~$

echo 1024 > /proc/sys/vm/nr_hugepages

echo "vm.nr_hugepages=1024" > /etc/sysctl.d/hugepages.conf

total huge pages

clyso@compute-21:/etc/sysctl.d# grep HugePages_Total /proc/meminfo

HugePages_Total: 1024

clyso@compute-21:/etc/sysctl.d#

free hugepages

clyso@compute-21:/etc/sysctl.d# grep HugePages_Free /proc/meminfo

HugePages_Free: 1024

clyso@compute-21:/etc/sysctl.d#


free memory

clyso@compute-21:/etc/sysctl.d# grep MemFree /proc/meminfo

MemFree: 765177380 kB

clyso@compute-21:/etc/sysctl.d#

How to make huge pages available in kubernetes?

restart kubernetes kublet on worker node

sudo systemctl restart kubelet.service



Allocated resources

clyso@compute-21:~$ kubectl describe node compute-21 | grep -A 8 "Allocated resources:"

Allocated resources:

  (Total limits may be over 100 percent, i.e., overcommitted.)

  Resource           Requests      Limits

  --------           --------      ------

  cpu                4950m (10%)   15550m (32%)

  memory             27986Mi (3%)  292670Mi (37%)

  ephemeral-storage  0 (0%)        0 (0%)

  hugepages-1Gi      0 (0%)        0 (0%)

  hugepages-2Mi      400Mi (19%)   400Mi (19%)

clyso@compute-21:~$

Capacity

clyso@compute-21:~$ kubectl describe node compute-21 | grep -A 13 "Capacity:"

Capacity:

  cpu:                48

  ephemeral-storage:  1536640244Ki

  hugepages-1Gi:      0

  hugepages-2Mi:      2Gi

  memory:             792289900Ki

  pods:               110

Allocatable:

  cpu:                48

  ephemeral-storage:  1416167646526

  hugepages-1Gi:      0

  hugepages-2Mi:      2Gi

  memory:             790090348Ki

  pods:               110

clyso@compute-21:~$

Sources:

https://kubernetes.io/docs/tasks/manage-hugepages/scheduling-hugepages/

https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/5/html/tuning_and_optimizing_red_hat_enterprise_linux_for_oracle_9i_and_10g_databases/sect-oracle_9i_and_10g_tuning_guide-large_memory_optimization_big_pages_and_huge_pages-configuring_huge_pages_in_red_hat_enterprise_linux_4_or_5

Author 

Posted on 

21. April 2022

Categories 

kubernetes

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