deptool ping¶

deptool ping [--limit <hosts>]... [--] [<dir>]

Description¶

Measure round-trip latencies to every host in the cluster. This measures the latency over the SSH connection, using the same agent protocol that the other commands use. It’s not an ICMP ping, which means it works even when ICMP ping is blocked. On the flip side, because pings travel over an SSH connection, this tool cannot measure packet loss.

See also deptool deploy for details about the cluster config tree directory <dir>. As with other commands, ping defaults to the last-used cluster when you omit it.

Output¶

The command outputs live statistics as it collects data, up to 150 pings per host:

a.example.com:   5.9 ms |   6.3 ms |   7.9 ms  (min/p50/p95 rtt, n=150)
b.example.com:   6.6 ms |   7.8 ms |  14.5 ms  (min/p50/p95 rtt, n=150)
c.example.com:  13.9 ms |  14.4 ms |  16.5 ms  (min/p50/p95 rtt, n=150)
d.example.com:  97.2 ms |  98.1 ms |  99.6 ms  (min/p50/p95 rtt, n=150)

It prints the minimum observed round-trip time in milliseconds (first column), the 50th percentile (second column), and 95th percentile (third column).

Options¶

--limit <hosts>¶

Limit the hosts to connect to. Can be provided multiple times, and supports a comma-separated list of hosts too. For example, in a cluster with hosts web1 through web5, passing --limit web1,web2 --limit web3 would exclude web4 and web5 from the measurement.