Questions tagged [cluster]
A computer cluster consists of a set of loosely connected computers that work together so that in many respects they can be viewed as a single system.
1,360
questions
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MaxScale doesn't connect to Galera Cluster
I am working on a distributed HA cloud system and I have a Galera Cluster with 3 separated servers in Docker Swarm. It works as expected.
I have 3 separated services for the Galera members due to ...
- 131
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vote
0
answers
37
views
MariaDB Galera cluster with failed node
A client of mine asked a question that I'm not really sure how to answer correctly. His question is: In case of one node falls out of the cluster, stays offline for a few hours or days and then comes ...
- 1,028
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0
answers
49
views
Availability of CHROOT in Docker containers and clusters
Is the Linux tool chroot generally usable in a Docker container running in clusters and cloud platforms?
(background) I'm developing an application where I may need to use chroot inside a Docker ...
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5
votes
2
answers
118
views
Corosync/Pacemaker/DRBD Resilience Tuning
I have a DRBD cluster and one node was switched off for a couple of days. The single node ran fine without a hiccup. When i switch it on I got into a situation where all resources got stopped and one ...
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votes
1
answer
95
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Howto: Block or File replication across 3+ nodes without a SAN
The setup
I admin the backend for a website that currently exists on a single node using Nginx (webserver), Neo4J (database) and Wildfly (app server). The website is getting enough traffic that we ...
- 567
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answer
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Failover Cluster Manager - Location of the stored clusters
I have about a dozen clusters that i monitor daily. I use the Failover Cluster Manager under MMC for a dashboard view of the clusters.
Two things i am looking for.
Where are the cluster names that ...
- 202
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0
answers
63
views
Kubernetes tomcat cluster: skipping state transfer. No members active in cluster group
k8s StatefulSet:
apiVersion: v1
kind: Service
metadata:
name: my-web
labels:
app: my-web
spec:
ports:
- name: http
port: 8080
targetPort: 8080
selector:
app: my-web
...
- 111
0
votes
0
answers
60
views
Tomcat cluster in Kubernetes: fetchMembers Failed to open stream
Tomcat cluster in K8s:
Following https://cwiki.apache.org/confluence/display/tomcat/ClusteringCloud
added the following in tomcat server.xml:
<Cluster className="org.apache.catalina.ha.tcp....
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1
vote
1
answer
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Running a cluster 24x7 at full load. Possible damages? [closed]
Let us assume that we have a pool of some 50 computers with 6 cores and 12 threads each.
If someone plans to use it for intensive astrophysics simulation using all of its logical CPUs (50*12) for 24x7,...
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3
votes
2
answers
96
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There is no replication in a HA Cluster
I had the problem of unrelated data aborting in a HA cluster and my Mysql resource was in standalone on both nodes, I managed to solve the problem and both nodes are synchronized, the problem now is ...
- 111
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votes
0
answers
12
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error while downloading the file fron the cluster
protocol error: unexpected
my ~/.bashrc code is as:
# .bashrc
# Source global definitions
if [ -f /etc/bashrc ]; then
. /etc/bashrc
fi
# User specific aliases and functions
source /home/...
0
votes
0
answers
51
views
fix crm cluster in sles12sp5 for 12 node master slave configuration
When we try to add the additional servers 0f 6 004,005,006,104,105 & 106.to the existing server of primary 001, 002 & 003 Secondary 101,102 & 103.
crm configure show
node 1: pbh001
...
1
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0
answers
63
views
MySql Service Not Starting in cluster with DRBD
I have a high availability cluster with two nodes configured, after a maintenance carried out by an external company when restarting the system my mysql resource stopped working.
when executing the ...
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vote
1
answer
72
views
mysql NDB backup fail
I'm trying to abort a backup on a NDB cluster like this:
ndb_mgm> abort backup 2304081512
Abort of backup 2304081512 ordered
But there is no change, the backup seems to be stalled :
ndb_mgm> ...
- 145
0
votes
0
answers
127
views
SLURM / NFS based computing cluster with disk uniterruptible sleep issues (state : D)
Context :
We have a computing cluster based on 7 servers, running Debian 11:
a storage (HDD NAS, ~500TB, RAID5, LVM)
a frontal server, running SLURM, nfs-common
5 nodes on which the storage is ...
2
votes
1
answer
785
views
How to parse and filter on dict values on Ansible?
I'm currently working on a playbook to create a K8s cluster on Nutanix Prism Central. Everything run smoothly but i face an issue while a VLAN exists on one or more clusters.
In my case, a VLAN is ...
- 343
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votes
1
answer
170
views
Windows Server quorum concept and split-brain issue prevention
I saw a similar question asked here that is closely related, but the provided answer doesn't entirely address my doubts.
Assume a 3 node cluster is configured without a witness node, and all nodes are ...
- 103
1
vote
0
answers
230
views
Can not start etcd cluster when setting up a HA K8S cluster
I am following this article to set up a HA k8s cluster:
Guide: Kubernetes Multi-Master HA Cluster with kubeadm
I have three master nodes(3,4,5) and four worker nodes(2,6,7,8) (one of the worker nodes ...
- 111
0
votes
0
answers
33
views
STONITH Block Device daemon (SBD) actions based on conditions
Is there any detailed description how SBD reacts to various conditions/issues? sbd(8) is not very detailed I would say. I can't read the source which is here: https://github.com/ClusterLabs/sbd/blob/...
- 547
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0
answers
23
views
Setting up Rhel cluster for high perfomance and load balancing
I am having 7 servers with RHEL, I want to setup a cluster for those. We need cluster for:
1: high Perfomance
2: load balancing
I have NAS for shared storage. I want to setup 1 server as visulization ...
- 5
0
votes
1
answer
113
views
Setting up slurm with 2 different nodes and 2 different partation on 1 physical server
I have a requirement for setting up slurm on one physical server, with 2 different partation and 2 main node so, need to have,
partation1 wihich need to have node1 and need to be used by group1 user
...
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0
votes
1
answer
154
views
ceph-deploy install command fails with [ceph_deploy][ERROR ] RuntimeError: configparser.NoSectionError: No section: 'main'
Command ceph-deploy install admin datanode_dn2 fails with output:
[ceph_deploy.install][INFO ] Distro info: rocky 9.1 blue onyx
[admin][INFO ] installing Ceph on admin
[admin][INFO ] Running ...
- 133
0
votes
0
answers
68
views
SQL always on cluster on RODC Environment
We are setting up an branch office which has couple of apps and DB servers, and RODC for authentication. we need to configure SQL always on cluster in that branch office. I have done it for RWDC but ...
- 327
0
votes
1
answer
100
views
Zabbix DB connection support DNS SRV Records
I have Zabbix Mysql 3 node Innodb cluster, which gives 3 DNS SRV Records with Mysql Router endpoints. I need to configure Zabbix server and web DB connection as DB host (e.g _mysql._tcp.example.com), ...
- 1
0
votes
1
answer
599
views
"CrashLoopBackOff" while deploying mysql on multi-node cluster
This is my configmap.yaml file:
apiVersion: v1
kind: ConfigMap
metadata:
name: mysql
labels:
app: mysql
app.kubernetes.io/name: mysql
data:
primary.cnf: |
# Apply this config only ...
- 377
-3
votes
1
answer
49
views
Can Auto-Scaling be considered an advanced concept of Clustering?
Since using auto-scaling, it seemed to be no different from clustering except that the scale is automatically changed.
I think what they have in common is that both increase availability by ...
-3
votes
2
answers
122
views
Heterogeneous Cluster Solution for R&D
I work in a research laboratory with multiple physical machines with different specifications. The machines have different CPUs (some Intel, some AMD), different RAM sizes, some have discrete GPUs, ...
- 55
0
votes
1
answer
120
views
Linux missing lvm
hello so i have a ubuntu hpc cluster and i got a problem with storage
whenever i try to access the storage from my compute nodes i cant i keep getting this error
mount:mounting 192.168.100.211:/cm/...
0
votes
0
answers
277
views
MySQL replication fails with connection error when server has second IP address
For a few days I've been struggling with a MySQL + Docker + ClusterIP problem. I'm trying to create a failover for my servers. If Server1 fails, Server2 should take over automatically. Both servers ...
- 135
0
votes
1
answer
306
views
Can I run a Select query on an SQL dump?
Here is my issue. I've a backup system, that creates an SQL Dump from a DB cluster every day. Works fine, yade yade. The cluster died one day and we realized, the sql dump were wrong for the past 1 ...
- 1,028
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47
views
openvpn access server cluster cannot create a unique ovpn file for all server
i install multiple openvpn access server 2.11 on ubuntu 20 and install mysql for cluster it now i have 5 openvpn server in 1 cluster
openvpn_as 2.11
ubuntu 20
1.my problem is ovpn file that download ...
0
votes
0
answers
23
views
transparent management of scratch fs on cluster node
I have a cluster made of 5 node, the node 1 host a big file-system exported via NFS to other nodes.
The other nodes have a fast nvme disks used for scratch.
I would like to encourage users to work on ...
- 101
0
votes
0
answers
59
views
Automate logging in to separate cluster nodes for monitoring (htop)
I login to the cluster and login to say N=3 nodes. Then, I laboriously open the N
panes in eg tmux or kitty, ssh onto the login node to each, then ssh onto the specific node for each of the N nodes, ...
- 111
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0
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301
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How to set HA LVM in RHEL 9 / Rocky Linux 9
I try to set HA LVM (active/passive) in Rocky Linux 9 for my cluster that have 2 nodes (node1 and node2).
I'm using iSCSI shared storage to set HA LVM in this cluster.
I set HA LVM with following ...
1
vote
1
answer
962
views
ssh directly into a specific node on a cluster, without first ssh into login node?
I usually log on to a cluster, start a slurm interactive job, then I am able to ssh into specific running nodes.
My questions is, is it generally possible to ssh into a specific node from my local ...
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0
answers
115
views
How do you upgrade your openstack cluster?
I'm taking care of a small 3 nodes(compute/storage/control) openstack cluster installed via Ubuntu packages.
When upgrading between openstack major versions or OS updates that include rebooting the ...
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1
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0
answers
78
views
MongoS refusing connections during network split
I am exploring sharded MongoDB clusters, and I have trouble understanding MongoS's behavior during a network split.
My test environment works as expected until I simulate a network split.
In the "...
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votes
1
answer
175
views
How to have two applications accessing a shared drive without isci config or shared lun?
We have a 2-node cluster configured using red hat high availability (pacemaker) but without shared storage i.e. each of the node has its own disk /dev/sda and /dev/sdb.
We are not allowed to configure ...
0
votes
1
answer
364
views
Virtual IP in pacemaker cluster not pinging
I have two Linux rhel8 servers with pacemaker/corosync/pcsd installed. I've used the ocf:heartbeat:IPaddr2 resource to create a virtual IP for the cluster.
I have a similar setup on a few older ...
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votes
2
answers
533
views
Errors about Making Failover-Cluster on Hyper-V with Win-Server-19 on Powershell
Good day. On my working have task to make Cluster incide cluster on Hyper-V.
Started to do this. Made 3 virtual PC on Hyper-V, download Failovering cluster by command:"Install-WindowsFeature ...
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290
views
Not able to ssh into 2 Compute Nodes on HPE Cluster
I recently added two new Compute Nodes on HPE CLuster , But surprisingly, I am Unable to ssh into the new Compute Nodes from the Head Node .
[Unable to SSH to new Compute Nodes][1]
(base) [root@hn001 ~...
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votes
3
answers
401
views
How to create shared folder with Linux Samba Cluster that is accessible by Windows? (Two PCs in cluster with one IP)
does anyone know how to create a shared folder in any distribution of Linux that could be accessible by Windows and would be HA (high available)?
Background:
I have Windows Server cluster and it needs ...
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votes
1
answer
673
views
kube-apiserver logs that certificate has expired but it's not
kube-apiserver pod print following log:
authentication.go:104] Unable to authenticate the request due to an error: x509: certificate has expired or is not yet valid
I already renewed all certs
renew ...
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votes
1
answer
436
views
Multi-Master K8S cluster fails when half of the masters are down
i have a 4 masters HA K8S cluster , (accross 2 datacenters , 2 in each site) , but the kubectl command stops working after shuting down 2 masters , is this the expected behaviour?
I want the cluster ...
- 3
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vote
1
answer
154
views
HPC master node no infiniband network influence on compute nodes - Slurm management
I'm writing because I'm facing an issue that I cannot solve trying to configure a cluster with a master node ( or Frontend node ) as a Virtual machine managing nodes with infiniband network.
I use ...
- 121
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0
answers
144
views
How to use "fence_vbox" as fencing device in Virtual Box?
I'm just learning about clustering. And now I'm so curious about fencing device using stonith fence_vbox for Virtual Box. I'm searching for documentation about fence_vbox, but no found specific ...
7
votes
1
answer
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views
Error when create a MicroK8s cluster : Connection failed. The hostname (xx) of the joining node does not resolve to the IP "xx". Refusing join (400)
I have installed microk8s(1.24/stable) on two machines.
The ip of the two machines are：172.29.99.187, 172.29.99.188.
I operate the command at 172.29.99.187：microk8s add-node
Output:
From the node you ...
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1
answer
77
views
Configure and connect fence device through proxy server?
I'm setting up a cluster with Pacemaker and Corosync (from Clusterlabs).
It works fine but i need to configure the fencing.
Servers run on a VMWare ESXi infrastructure.
I have a frontend server (with ...
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0
votes
1
answer
690
views
Pacemaker Virtual IP suddenly Failed
I am new in cluster.
We are running SAP Application in HA Cluster (have 2 nodes in cluster) using pacemaker. Node1 if it runs as a master always restart for a few times. After we check pacemaker logs, ...
0
votes
1
answer
350
views
Stopping DRBD so I can run some tests with a VM
We have two servers I inherited, both running DRBD and each then running KVM virtual machines.
I would love to stop a VM running on server1, and bring up just the 1 VM on server2 for some tests. ...
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