This section contains frequently asked questions about Metricbeat. Also check out the Metricbeat discussion forum.

Fix for open /compat/linux/proc: no such file or directory error on FreeBSD?edit

The system metricsets rely a Linux comparability layer to retrieve metrics on FreeBSD. You need to mount the Linux procfs filesystem using the following commands. You may want to add these filesystems to your /etc/fstab so they are mounted automatically.

sudo mount -t procfs proc /proc
sudo mkdir -p /compat/linux/proc
sudo mount -t linprocfs /dev/null /compat/linux/proc

Need to limit bandwidth used by Metricbeat?edit

If you need to limit bandwidth usage, we recommend that you configure the network stack on your OS to perform bandwidth throttling.

For example, the following Linux commands cap the connection between Metricbeat and Logstash by setting a limit of 50 kbps on TCP connections over port 5044:

tc qdisc add dev $DEV root handle 1: htb
tc class add dev $DEV parent 1:1 classid 1:10 htb rate 50kbps ceil 50kbps
tc filter add dev $DEV parent 1:0 prio 1 protocol ip handle 10 fw flowid 1:10
iptables -A OUTPUT -t mangle -p tcp --dport 5044 -j MARK --set-mark 10

Using OS tools to perform bandwidth throttling gives you better control over policies. For example, you can use OS tools to cap bandwidth during the day, but not at night. Or you can leave the bandwidth uncapped, but assign a low priority to the traffic.

Error loading config file?edit

You may encounter errors loading the config file on POSIX operating systems if:

See Config File Ownership and Permissions for more about resolving these errors.

Found Unexpected or Unknown Characters?edit

Either there is a problem with the structure of your config file, or you have used a path or expression that the YAML parser cannot resolve because the config file contains characters that aren’t properly escaped.

If the YAML file contains paths with spaces or unusual characters, wrap the paths in single quotation marks (see Wrap Paths in Single Quotation Marksedit).

Also see the general advice under YAML Tips and Gotchas.

Logstash connection doesn’t work?edit

You may have configured Logstash or Metricbeat incorrectly. To resolve the issue:

@metadata is missing in Logstash?edit

Logstash outputs remove @metadata fields automatically. Therefore, if Logstash instances are chained directly or via some message queue (for example, Redis or Kafka), the @metadata field will not be available in the final Logstash instance.

To preserve @metadata fields, use the Logstash mutate filter with the rename setting to rename the fields to non-internal fields.

Difference between Logstash and Beats?edit

Beats are lightweight data shippers that you install as agents on your servers to send specific types of operational data to Elasticsearch. Beats have a small footprint and use fewer system resources than Logstash.

Logstash has a larger footprint, but provides a broad array of input, filter, and output plugins for collecting, enriching, and transforming data from a variety of sources.

For more information, see the Logstash Introduction and the Beats Overview.

SSL client fails to connect to Logstash?edit

The host running Logstash might be unreachable or the certificate may not be valid. To resolve your issue:

Common SSL-Related Errors and Resolutionsedit

Here are some common errors and ways to fix them:

x509: cannot validate certificate for <IP address> because it doesn’t contain any IP SANsedit

This happens because your certificate is only valid for the hostname present in the Subject field.

To resolve this problem, try one of these solutions:

getsockopt: no route to hostedit

This is not a SSL problem. It’s a networking problem. Make sure the two hosts can communicate.

getsockopt: connection refusededit

This is not a SSL problem. Make sure that Logstash is running and that there is no firewall blocking the traffic.

No connection could be made because the target machine actively refused itedit

A firewall is refusing the connection. Check if a firewall is blocking the traffic on the client, the network, or the destination host.