f4f0373579
Writing points that were not sorted by time could cause very high CPU usages and increased latencies because each point inserted would cause the in-memory cache to be resorted. The worst case would be writing a large batch of N points in reverse time order which would invoke N sorts of the slice. This patch keeps track of which slices need to be sorted and sorts them once at the end. In the previous example, the N sorts becomes one. There is still a pathalogical case that would require N/2 sorts. For example, 10000 points split across 5000 series. Each series has two points that are in reverse time order. This would incur 5000 sorts still. Fixes #3159 |
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| .. | ||
| internal | ||
| README.md | ||
| batcher.go | ||
| batcher_test.go | ||
| config.go | ||
| doc.go | ||
| meta.go | ||
| meta_test.go | ||
| monitor.go | ||
| points.go | ||
| points_test.go | ||
| query_executor.go | ||
| query_executor_test.go | ||
| shard.go | ||
| shard_test.go | ||
| snapshot_writer.go | ||
| store.go | ||
| store_test.go | ||
| tx.go | ||
README.md
Line Protocol
The line protocol is a text based format for writing points to InfluxDB. Each line defines a single point.
Multiple lines must be separated by the newline character \n. The format of the line consists of three parts:
[key] [fields] [timestamp]
Each section is separated by spaces. The minimum required point consists of a measurement name and at least one field. Points without a specified timestamp will be written using the server's local timestamp. Timestamps are assumed to be in nanoseconds unless a precision value is passed in the query string.
Key
The key is the measurement name and any optional tags separated by commas. Measurement names, tag keys, and tag values must escape any spaces or commas using a backslash (\). For example: \ and \,. All tag values are stored as strings and should not be surrounded in quotes.
Tags should be sorted by key before being sent for best performance. The sort should match that from the Go bytes.Compare function (http://golang.org/pkg/bytes/#Compare).
Examples
# measurement only
cpu
# measurment and tags
cpu,host=serverA,region=us-west
# measurment with commas
cpu\,01,host=serverA,region=us-west
# tag value with spaces
cpu,host=server\ A,region=us\ west
Fields
Fields are key-value metrics associated with the measurement. Every line must have at least one field. Multiple fields must be separated with commas and not spaces.
Field keys are always strings and follow the same syntactical rules as described above for tag keys and values. Field values can be one of four types. The first value written for a given field on a given measurement defines the type of that field for all series under that measurement.
- integer - Numeric values that do not include a decimal. (e.g. 1, 345, 2015, -10)
- float - Numeric values that include a decimal. (e.g. 1.0, -3.14, 6.0+e5). Note that all values must have a decimal even if the decimal value is zero (1 is an integer, 1.0 is a float).
- boolean - A value indicating true or false. Valid boolean strings are (t, T, true, TRUE, f, F, false, and FALSE).
- string - A text value. All string values must be surrounded in double-quotes
". If the string contains a double-quote, it must be escaped with a backslash, e.g.\".
# integer value
cpu value=1
# float value
cpu_load value=1.2
# boolean value
error fatal=true
# string value
event msg="logged out"
# multiple values
cpu load=10.0,alert=true,reason="value above maximum threshold"
Timestamp
The timestamp section is optional but should be specified if possible. The value is an integer representing nanoseconds since the epoch. If the timestamp is not provided the point will inherit the server's local timestamp.
Some write APIs allow passing a lower precision. If the API supports a lower precision, the timestamp may also be an integer epoch in microseconds, milliseconds, seconds, minutes or hours.
Full Example
A full example is shown below.
cpu,host=server01,region=uswest value=1.0 1434055562000000000
cpu,host=server02,region=uswest value=3.0 1434055562000010000
In this example the first line shows a measurement of "cpu", there are two tags "host" and "region, the value is 1.0, and the timestamp is 1434055562000000000. Following this is a second line, also a point in the measurement "cpu" but belonging to a different "host".
cpu,host=server\ 01,region=uswest value=1.0,msg="all systems nominal"
cpu,host=server\ 01,region=us\,west value_int=1
In these examples, the "host" is set to server 01. The field value associated with field key msg is double-quoted, as it is a string. The second example shows a region of us,west with the comma properly escaped. In the first example value is written as a floating point number. In the second, value_int is an integer.