github.com/influxdata/telegraf@v1.30.3/docs/FAQ.md (about) 1 # Frequently Asked Questions 2 3 ## When is the next release? When will my PR or fix get released? 4 5 Telegraf has four minor releases a year in March, June, September, and 6 December. In between each of those minor releases, there are 2-4 bug fix 7 releases that happen every 3 weeks. 8 9 This [Google Calendar][] is kept up to date for upcoming releases dates. 10 Additionally, users can look at the [GitHub milestones][] for the next minor 11 and bug fix release. 12 13 PRs that resolves issues are released in the next release. PRs that introduce 14 new features are held for the next minor release. Users can view what 15 [GitHub milestones][] a PR belongs to to determine the release it will go out 16 with. 17 18 [Google Calendar]: https://calendar.google.com/calendar/embed?src=c_1ikq7u4f5c4o6mh9ep4duo3avk%40group.calendar.google.com 19 [GitHub milestones]: https://github.com/influxdata/telegraf/milestones 20 21 ## How can I filter or select specific metrics? 22 23 Telegraf has options to select certain metrics or tags as well as filter out 24 specific tags or fields: 25 26 - **Selectors** allow a user to include or exclude entire metrics based on the 27 metric name or tag key/pair values. 28 - **Modifiers** allow a user to remove tags and fields based on specific keys, 29 with glob support. 30 31 For more details and examples, see the [Metric Filtering][metric filtering] 32 section in the docs. 33 34 ## Could not find a usable config.yml, you may have revoked the CircleCI OAuth app 35 36 This is an error from CircleCI during test runs. 37 38 To resolve the error, you need to log back into CircleCI with your 39 username/password if that is how you log in or if you use GitHub log, re-create 40 your oauth/re-login with github. 41 42 That should regenerate your token and then allow you to push a commit or close 43 and reopen this PR and tests should run. 44 45 ## What does "Context Deadline exceeded (Client.Timeout while awaiting headers)" mean? 46 47 This is a generic error received from Go's HTTP client. It is generally the 48 result of a network blip or hiccup as a result of a DNS, proxy, firewall, 49 and/or other network issue. 50 51 The error should be temporary and Telegraf will recover shortly after without 52 the loss of data. 53 54 ## How do I set the timestamp format for parsing data? 55 56 Telegraf's `timestamp_format` config option requires the use 57 [Go's reference time][go ref time] to correctly translate the timestamp. For 58 example, if you have the time: 59 60 ```s 61 2023-03-01T00:00:42.586+0800 62 ``` 63 64 A user needs the timestamp format: 65 66 ```s 67 2006-01-02T15:04:05.000-0700 68 ``` 69 70 User's can try this out in the [Go playground][playground]. 71 72 [go ref time]: https://pkg.go.dev/time#pkg-constants 73 [playground]: https://goplay.tools/snippet/hi9GIOG_gVQ 74 75 ## Q: How can I monitor the Docker Engine Host from within a container? 76 77 You will need to setup several volume mounts as well as some environment 78 variables: 79 80 ```shell 81 docker run --name telegraf \ 82 -v /:/hostfs:ro \ 83 -e HOST_ETC=/hostfs/etc \ 84 -e HOST_PROC=/hostfs/proc \ 85 -e HOST_SYS=/hostfs/sys \ 86 -e HOST_VAR=/hostfs/var \ 87 -e HOST_RUN=/hostfs/run \ 88 -e HOST_MOUNT_PREFIX=/hostfs \ 89 telegraf 90 ``` 91 92 ## Q: Why do I get a "no such host" error resolving hostnames that other programs can resolve? 93 94 Go uses a pure Go resolver by default for [name resolution](https://golang.org/pkg/net/#hdr-Name_Resolution). 95 This resolver behaves differently than the C library functions but is more 96 efficient when used with the Go runtime. 97 98 If you encounter problems or want to use more advanced name resolution methods 99 that are unsupported by the pure Go resolver, you can switch to the cgo 100 resolver. 101 102 If running manually set: 103 104 ```shell 105 export GODEBUG=netdns=cgo 106 ``` 107 108 If running as a service add the environment variable to `/etc/default/telegraf`: 109 110 ```shell 111 GODEBUG=netdns=cgo 112 ``` 113 114 ## Q: How can I manage series cardinality? 115 116 High [series cardinality][], when not properly managed, can cause high load on 117 your database. Telegraf attempts to avoid creating series with high 118 cardinality, but some monitoring workloads such as tracking containers are are 119 inherently high cardinality. These workloads can still be monitored, but care 120 must be taken to manage cardinality growth. 121 122 You can use the following techniques to avoid cardinality issues: 123 124 - Use [metric filtering][] options to exclude unneeded measurements and tags. 125 - Write to a database with an appropriate [retention policy][]. 126 - Consider using the [Time Series Index][tsi]. 127 - Monitor your databases using the [show cardinality][] commands. 128 - Consult the [InfluxDB documentation][influx docs] for the most up-to-date techniques. 129 130 [series cardinality]: https://docs.influxdata.com/influxdb/v1.7/concepts/glossary/#series-cardinality 131 [metric filtering]: https://github.com/influxdata/telegraf/blob/master/docs/CONFIGURATION.md#metric-filtering 132 [retention policy]: https://docs.influxdata.com/influxdb/latest/guides/downsampling_and_retention/ 133 [tsi]: https://docs.influxdata.com/influxdb/latest/concepts/time-series-index/ 134 [show cardinality]: https://docs.influxdata.com/influxdb/latest/query_language/spec/#show-cardinality 135 [influx docs]: https://docs.influxdata.com/influxdb/latest/