Problem:
Setting up Multi datacenter using Docker Swarm. Each Docker Swarm at local DC is running with cassandra instances as 1/1+2 mode. There is a password connection between datacenters.
The seed nodes are DC-1:Node1, DC-2:Node1 (1+1) geo. DC-1:Node1, DC-1:Node3, DC-2:Node1, DC-2:Node3 in 1+2 mode of geo cluster ...
To discover the nodes, construct the topology between DC nodes via using cassandra storage port always expects bridge or host network. it does not work with OVERLAY network with PORT forwarding approach (Where it works for same DC with local network not across GEO sites).
It expect eithers host/bridge network, Otherwise it throws an exception as shown below
DEBUG [MessagingService-Outgoing-site-cassandra-A/15.29.8.10-Gossip] 2020-12-04 09:49:11,325
OutboundTcpConnection.java:546 - Unable to connect to site-cassandra-B/15.29.8.10
java.net.ConnectException: Connection refused
at sun.nio.ch.Net.connect0(Native Method) ~[na:1.8.0_262]
at sun.nio.ch.Net.connect(Net.java:454) ~[na:1.8.0_262]
at sun.nio.ch.Net.connect(Net.java:446) ~[na:1.8.0_262]
at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:645) ~[na:1.8.0_262]
at org.apache.cassandra.net.OutboundTcpConnectionPool.newSocket(OutboundTcpConnectionPool.java:146) ~
[apache-cassandra-3.11.4.jar:3.11.4]
at org.apache.cassandra.net.OutboundTcpConnectionPool.newSocket(OutboundTcpConnectionPool.java:132) ~
[apache-cassandra-3.11.4.jar:3.11.4]
at org.apache.cassandra.net.OutboundTcpConnection.connect(OutboundTcpConnection.java:434) [apache-
cassandra-3.11.4.jar:3.11.4]
at org.apache.cassandra.net.OutboundTcpConnection.run(OutboundTcpConnection.java:262) [apache-
cassandra-3.11.4.jar:3.11.4]
`
Workaround:
After we setup bridge network between geo-sites, it is able to discover and nodetool status shows two DC with proper cassandra instances with their replication configured % value.
I would like to know the reason of why cassandra is forcing to have
bridge or host based network why not with overlay base port forwarding
approach?
Thanks
Suresh Perumal
Related
I have the following setup:
Raspi with Docker and multiple Containers connected to my Router. Some containers are on a MACVLAN network and receive regular IP Address in my LAN (e.g. Pihole, Unbound, etc.), some are on bridged networks and expose certain ports (Portainer, nginx, etc.)
Router LAN (192.x.y.0/24)
|Raspi (192.x.y.5)
|Pihole (192.x.y.11)
|Webserver (192.x.y.20)
|Wireguard (192.x.y.13) - (VPN: 10.x.y.0/32, DNS 192.x.y.11) - (Allowed IPs: 192.x.y.0/24)
|
|Portainer (bridged - exposing 8000, 9000, 9443)
|NGINX (bridged - exposing 81, 80, 443)
When I connect a client through Wireguard,
I can access the internet (Pihole on 192.x.y.11 works as DNS - adblocking works)
I can access Piholes webUI on 192.x.y.11
I can access my webserver on 192.x.y.20
NOT working:
I cannot access the Portainer UI or NGINX UI on their respective forwarded IP:ports e.g. 192.x.y.5:81 for NGINX
What is missing in any config? I found nothing solving this issue - please help!
So I'm currently running on my local Kubernetes cluster (running on docker) the stable/consul chart from helm.
$ helm install -n wet-fish --namespace consul stable/consul
This creates two services
==> v1/Service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
wet-fish-consul ClusterIP None <none> 8500/TCP,8400/TCP,8301/TCP,8301/UDP,8302/TCP,8302/UDP,8300/TCP,8600/TCP,8600/UDP 0s
wet-fish-consul-ui NodePort 10.110.229.223 <none> 8500:30276/TCP
So this means I can run localhost:30276 and see the consul ui.
Now I'm running on my local machine
$ consul agent -dev -config-dir=./consul.d -node=machine
$ consul join 127.0.0.1:30276
This just results in:
Error joining address '127.0.0.1:30276': Unexpected response code: 500 (1 error occurred:
* Failed to join 127.0.0.1: received invalid msgType (72), expected pushPullMsg (6) from=127.0.0.1:30276
)
Failed to join any nodes.
and
2020/01/17 15:17:35 [WARN] agent: (LAN) couldn't join: 0 Err: 1 error occurred:
* Failed to join 127.0.0.1: received invalid msgType (72), expected pushPullMsg (6) from=127.0.0.1:30276
2020/01/17 15:17:35 [ERR] http: Request PUT /v1/agent/join/127.0.0.1:30276, error: 1 error occurred:
* Failed to join 127.0.0.1: received invalid msgType (72), expected pushPullMsg (6) from=127.0.0.1:30276
from=127.0.0.1:59693
There must be a way to have a local consul agent running that can connect to the k8s consul server...
This is on a Mac, so networking isn't as good....
There may be two problems here, the first is that consul agent -dev starts the agent in dev mode. By default dev mode is going to start both a server and an agent. This might be part of the reason behind the error.
The other problem could be due to localhost, the server running in Kubernetes will attempt to health check local agents. It needs to be able to ping the local agent, so even if you manage to join in the first step, it would probably fail health checks.
I agree about networking on Mac it does not make things easy, one thing you will probably have to do is set the advertise address for the local agent (non kube). Docker for mac has a host name docker.for.mac.localhost which is a routable ip to the local machine from a container. When starting the local agent if you set the advertise address to the ip value of that host Kubernetes Consul server should be able to route to the locally running agent.
Potential fix:
1. Ensure local agent is starting in client mode (manually configure not -dev)
2. Set advertise advertise address to an ip address which is routable from Kubernetes docker.for.mac.localhost
Give me a shout if that does not work for you, I have used a setup like this myself, 9/10 it is networking between Docker and the local machine.
Kind regards,
Nic
I have a bare metal server on Hetzner with IP 5.6.7.8 and 8 additional IPs reserved for me.
IPs: 1.2.3.144 to 1.2.3.151
subnet: 1.2.3.144/29
netmask: 255.255.255.248
broadcast: 1.2.3.151
gateway: 5.6.7.8
Now I want to create Docker network with type macvlan
docker network create macvlan --subnet=1.2.3.144/29 --gateway=5.6.7.8 -o parent=enp0s31f6 macvlan1
But this command causes an error
no matching subnet for gateway 5.6.7.8
Note when I set for example IP 1.2.3.150 and gateway 5.6.7.8 on a virtual machine on the host, it works correctly! but I can't set this none matching gateway in Docker network create command.
I have 2 VMs.
On the first I run:
docker swarm join-token manager
On the second I run the result from this command.
i.e.
docker swarm join --token SWMTKN-1-0wyjx6pp0go18oz9c62cda7d3v5fvrwwb444o33x56kxhzjda8-9uxcepj9pbhggtecds324a06u 192.168.65.3:2377
However, this outputs:
Error response from daemon: rpc error: code = Unavailable desc = all SubConns are in TransientFailure, latest connection error: connection error: desc = "transport: Error while dialing dial tcp 192.168.65.3:2377: connect: connection refused"
Any idea what's going wrong?
If it helps I'm spinning up these VMs using Vagrant.
Just add the port to firewall on master side
firewall-cmd --add-port=2377/tcp --permanent
firewall-cmd --reload
Then again try docker swarm join on second VM or node side
I was facing similar issue. and I spent couple of hours to figure out the root cause and share to those who may have similar issues.
Environment:
Oracle Cloud + AWS EC2 (2 +2)
OS: 20.04.2-Ubuntu
Docker version : 20.10.8
3 dynamic public IP+ 1 elastic IP
Issues
create two instances on the Oracle cloud at beginning
A instance (manager) docker swarm init --advertise-addr success
B instance (worker) docker join as worker is worker success
when I try to promo B as manager, encountered error
Unable to connect to remote host: No route to host
5. mesh routing is not working properly.
Investigation
Suspect it is related to network/firewall/Security group/security list
ssh to B server (worker), telnet (manager) 2377, with same error
Unable to connect to remote host: No route to host
3. login oracle console and add ingress rule under security list for all of relative port
TCP port 2377 for cluster management communications
TCP and UDP port 7946 for communication among nodes
UDP port 4789 for overlay network traffic
4. try again but still not work with telnet for same error
5. check the OS level firewall. if has disable it.
systemctl ufw disable
6. try again but still not work with same result
7. I suspect there have something wrong with oracle cloud, then I decide try to use AWS install the same version of OS/docker
8. add security group to allow all of relative ports/protocol and disable ufw
9. test with AWS instance C (leader/master) + D (worker). it works and also can promote D to manager. mesh routing was also work.
10. confirm the issue with oracle cloud
11. try to join the oracle instance (A) to C as worker. it works but still cannot promote as manager.
12. use journalctl -f to investigate the log and confirm there have socket timeout from A/B (oracle instances) to AWS instance(C)
13. relook the A/B, found there have iptables block request
14. remove all of setup in the iptables
# remove the rules
iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -F
15. remove all of setup in the iptables
Root Cause
It caused by firewall either in cloud security/WAF/ACL level or OS firewall/rules. e.g. ufw/iptables
I did firewall-cmd --add-port=2377/tcp --permanent firewall-cmd --reload already on master side and was still getting the same error.
I did telnet <master ip> 2377 on worker node and then I did reboot on master.
Then it is working fine.
It looks like your docker swarm manager leader is not running on port 2377. You can check it by firing this command on your swarm manager leader vm. If it is working just fine then you will get similar output
[root#host1]# docker node ls
ID HOSTNAME STATUS AVAILABILITY MANAGER STATUS
tilzootjbg7n92n4mnof0orf0 * host1 Ready Active Leader
Furthermore you can check the listening ports in leader swarm manager node. It should have port tcp 2377 for cluster management communications and tcp/udp port 7946 for communication among nodes opened.
[root#host1]# netstat -ntulp | grep dockerd
tcp6 0 0 :::2377 :::* LISTEN 2286/dockerd
tcp6 0 0 :::7946 :::* LISTEN 2286/dockerd
udp6 0 0 :::7946 :::* 2286/dockerd
In the second vm where you are configuring second swarm manager you will have to make sure you have connectivity to port 2377 of leader swarm manager. You can use tools like telnet, wget, nc to test the connectivity as given below
[root#host2]# telnet <swarm manager leader ip> 2377
Trying 192.168.44.200...
Connected to 192.168.44.200.
For me I was on linux and windows. My windows docker private network was the same as my local network address. So docker daemon wasn't able to find in his own network the master with the address I was giving to him.
So I did :
1- go to Docker Desktop app
2- go to Settings
3- go to Resources
4- go to Network section and change the Docker subnet address (need to be different from your local subnet address).
5- Then apply and restart.
6- use the docker join on the worker again.
Note: All this steps are performed on the node where the error appear. Make sure that the ports 2377, 7946 and 4789 are opens on the master (you can use iptables or ufw).
Hope it works for you.
I have been trying to setup a geo replication with glusterfs servers. Everything worked as expected in my test environment, on my staging environment, but then i tried the production and got stuck.
Let say I have
gluster fs server is on public ip 1.1.1.1
gluster fs slave is on public 2.2.2.2, but this IP is on interface eth1
The eth0 on gluster fs slave server is 192.168.0.1.
So when i start the command on 1.1.1.1 (firewall and ssh keys are set properly)
gluster volume geo-replication vol0 2.2.2.2::vol0 create push-pem
I get an error.
Unable to fetch slave volume details. Please check the slave cluster and slave volume.
geo-replication command failed
The error is not that important in this case, the problem is the slave IP address
2015-03-16T11:41:08.101229+00:00 xxx kernel: TCP LOGDROP: IN= OUT=eth0 SRC=1.1.1.1 DST=192.168.0.1 LEN=52 TOS=0x00 PREC=0x00 TTL=64 ID=24243 DF PROTO=TCP SPT=1015 DPT=24007 WINDOW=14600 RES=0x00 SYN URGP=0
As you can see in the firewall drop log above, the port 24007 of the slave gluster daemon is advertised on private IP of the interface eth0 on slave server and should be the IP of the eth1 private IP. So master cannot connect and will time out
Is there a way to force gluster server to advertise interface eth1 or bind to it only?
I use cfengine and ansible to push configuration, so binding to Interface could be a better solution than IP, but whatever solution will do.
Thank you in advance.
I've encountered this issue but in a different context.
I was trying to geo-replicate two nodes which were both behind a NAT (AWS instances in different regions).
When the master connects to the slave via the public IP to check for volume compatability/size and other details, it retrieves the hostname of the slave, which usually resolves to something that only has meaning in that remote region.
Then it uses that hostname to dial back to the slave when later setting up the session, which fails, as that hostname resolves to a private IP in a different region.
My workaround for the issue was to use hostnames when creating the volumes, probing for peers, and establishing geo replication, and then add a /etc/hosts entry mapping slaves hostname which usually resolves to its private IP to its public IP, rather than it's private IP.
This gets you to the point where you establish a session, but I haven't had any luck actually getting it to sync, as it uses the wrong IP somewhere long the way again.
Edit:
I've actually managed to get it running by adding /etc/hosts hacks on both sides.
GlusterFS has no notion of the network layer. Check your routes. If the next-hop for your geo-replication slave is on eth1, then gluster will open a port on that interface for the slave IP address.
Also make sure your firewall is configured to forward geo-replication traffic on this port.