Common error messages
This topic describes common messages that may appear when installing and running Consul. Errors usually they indicate an issue in your network or in your server's configuration. Refer to the Troubleshooting Guide for help resolving error messages that do not appear on this page.
For common errors messages related to Kubernetes, refer to Common errors on Kubernetes.
Configuration file errors
The following errors are related to misconfigured files.
Multiple network interfaces
Your server has multiple active network interfaces. Consul needs to know which interface to use for local LAN communications. Add the bind
option to your configuration.
Tip: If your server does not have a static IP address, you can use a go-sockaddr template as the argument to the bind
option, e.g. "bind_addr": "{{GetInterfaceIP \"eth0\"}}"
.
Configuration syntax errors
There is a syntax error in your configuration file. If the error message doesn't identify the exact location in the file where the problem is, try using jq to find it, for example:
Invalid host name
Add the node name
option to your agent configuration and provide a valid DNS name.
I/O timeouts
If the Consul client and server are on the same LAN, then most likely, a firewall is blocking connections to the Consul server.
If they are not on the same LAN, check the retry_join
settings in the Consul client configuration. The client should be configured to join a cluster inside its local network.
Deadline exceeded
These error messages indicate a general performance problem on the Consul server. Make sure you are monitoring Consul telemetry and system metrics according to our monitoring guide. Increase the CPU or memory allocation to the server if needed. Check the performance of the network between Consul nodes.
Too many open files
On a busy cluster, the operating system may not provide enough file descriptors to the Consul process. You will need to increase the limit for the Consul user, and maybe the system-wide limit as well. A good guide for Linux can be found here.
Or, if you are starting Consul from systemd
, you could add LimitNOFILE=65536
to the unit file for Consul. You can see our example unit file here.
Snapshot close error
Our RPC protocol requires support for a TCP half-close in order to signal the other side that they are done reading the stream, since we don't know the size in advance. This saves us from having to buffer just to calculate the size.
If a host does not properly implement half-close you may see an error message [ERR] consul: Failed to close snapshot: write tcp <source>-><destination>: write: broken pipe
when saving snapshots. This should not affect saving and restoring snapshots.
This has been a known issue in Docker, but may manifest in other environments as well.
ACL not found
This indicates that you have ACL enabled in your cluster, but you aren't passing a valid token. Make sure that when creating your tokens that they have the correct permissions set. In addition, you would want to make sure that an agent token is provided on each call.
TLS and certificates
The follow errors are related to TLS and certificate issues.
Incorrect certificate or certificate name
Make sure that your Consul clients and servers are using the correct certificates, and that they've been signed by the same CA. The easiest way to do this is to follow our guide.
If you generate your own certificates, make sure the server certificates include the special name server.dc1.consul
in the Subject Alternative Name (SAN) field. (If you change the values of datacenter
or domain
in your configuration, update the SAN accordingly.)
HTTP instead of HTTPS
You are attempting to connect to a Consul agent with HTTP on a port that has been configured for HTTPS.
If you are using the Consul CLI, make sure you are specifying "https" in the -http-addr
flag or the CONSUL_HTTP_ADDR
environment variable.
If you are interacting with the API, change the URI scheme to "https".
License warnings
You have installed an Enterprise version of Consul. If you are an Enterprise customer, provide a license key to Consul before it shuts down. Otherwise, install the open-source Consul binary instead.
Note: Enterprise binaries can be identified on our download site by the +ent
suffix.
Rate limit reached on the server
You may receive a RESOURCE_EXHAUSTED
error from the Consul server if the maximum number of read or write requests per second have been reached. Refer to Set a global limit on traffic rates for additional information. You can retry another server unless the number of retries is exhausted. If the number of retries is exhausted, you should implement an exponential backoff.
The RESOURCE_EXHAUSTED RPC response is translated into a 429 Too Many Requests
error code on the HTTP interface.
The server may respond as UNAVAILABLE
if it is the leader node and the global write request rate limit is reached. The solution is to apply an exponential backoff until the leader has capacity to serve those requests.
The UNAVAILABLE
RPC response is translated into a 503 Service Unavailable
error code on the RPC requests sent through HTTP interface.
Common errors on Kubernetes
The following error messages are specific to Kubernetes issues.
Unable to connect to the Consul client on the same host
If the pods are unable to connect to a Consul client running on the same host,
first check if the Consul clients are up and running with kubectl get pods
.
If you are still unable to connect
and see i/o timeout
or connection refused
errors when connecting to the Consul client on the Kubernetes worker,
this could be because the CNI (Container Networking Interface)
does not support
the use of hostPort
.
The IP 10.0.0.10
above refers to the IP of the host where the Consul client pods are running.
To work around this issue,
enable hostNetwork
in your Helm values.
Using the host network will enable the pod to use the host's network namespace without
the need for CNI to support port mappings between containers and the host.
Note: Using host network has security implications
as doing so gives the Consul client unnecessary access to all network traffic on the host.
We recommend raising an issue with the CNI you're using to add support for hostPort
and switching back to hostPort
eventually.
consul-server-connection-manager: ACL auth method login failed: error="rpc error: code = PermissionDenied desc = Permission denied"
If you see this error in the init container logs of service mesh pods, check that the pod has a service account name that matches its Service. For example, this deployment:
Will fail because the serviceAccountName
is does-not-match
instead of static-server
.