Subject: [InfluxData Community] [Collect] Input and output capacity of telegraf


Usually what I see as the limiting factor is how fast Telegraf can write to the output plugin.  The best way to gauge performance is to run Telegraf for a bit with the `internal` plugin enabled, this will create some new measurements including one called `internal_write`, here is an example:
```
internal_write,output=file buffer_limit=10000i,buffer_size=39i,errors=0i,metrics_added=65i,metrics_dropped=0i,metrics_filtered=0i,metrics_written=26i,write_time_ns=3938348i 1568833200000000000
```

If you look at the `write_time_ns` you can see how long it takes to write, and the agent's metric_batch_size divided by the write_time is the most you can send without falling behind.  If you are going to be proxying a lot of metrics I suggest keeping the `internal` plugin enabled and also monitoring the `metrics_dropped` field, if this is increasing then you have a problem.

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