Time Series Database:Troubleshooting

Deal with the "database name required" error message

If no database is specified for a SHOW query, the database name required error message is reported. To specify a database, use the ON clause in the SHOW statement, the USE <database_name> statement in the CLI, or the db parameter in an HTTP API request.

SHOW queries include the SHOW RETENTION POLICIES, SHOW SERIES, SHOW MEASUREMENTS, SHOW TAG KEYS, SHOW TAG VALUES, and SHOW FIELD KEYS statements.

Deal with the "max series per database exceeded: < >" error message

If the maximum number of series per database is exceeded during a write request, the max series per database exceeded: < > error message is reported. The maximum number of series per database is determined by the instance type of your instance.

The information displayed in the angle bracket (< >) shows the measurements and tag sets of the series that exceed the upper limit specified by max-series-per-database.

Deal with the "found < >, expected identifier at line < >, char < >" error message

• InfluxQL syntax

  If TSDB For InfluxDB® cannot find an expected identifier in a query, the found < >, expected identifier at line < >, char < > error message is reported. Identifiers can be continuous query names, database names, field keys, measurement names, retention policy names, subscription names, tag keys, or usernames. This error message prompts you to check your query syntax.

  Example

  > SELECT * FROM WHERE "blue"= true
  ERR: error parsing query: found WHERE, expected identifier at line 1, char 15

  In the preceding statement, a measurement name is missing between FROM and WHERE.

• InfluxQL keyword

  If one of the identifiers in a query is an InfluxQL keyword, the expected identifier error message is reported. If an identifier in your query is an InfluxQL keyword, enclose the identifier in double quotation marks (").

  Example

  > SELECT duration FROM runs
  ERR: error parsing query: found DURATION, expected identifier, string, number, bool at line 1, char 8

  In the preceding statement, the duration field key is an InfluxQL keyword. To prevent this error, enclose duration in double quotation marks (").

  > SELECT "duration" FROM runs

Deal with the "found < >, expected string at line < >, char < >" error message

If TSDB For InfluxDB® cannot find an expected string in a query, the found < >, expected string at line < >, char < > error message is reported.

Deal with the "mixing aggregate and non-aggregate queries is not supported" error message

If the SELECT statement includes both an aggregate function and a field or tag key that is not aggregated, the mixing aggregate and non-aggregate queries is not supported error message is reported.

An aggregate function returns a single aggregated value. No single value can be returned for a field or tag key that is not aggregated.

Examples

Raw data: The peg measurement includes the square and round fields and the force tag.

name: peg
---------
time                   square   round   force
2016-10-07T18:50:00Z281
2016-10-07T18:50:10Z4122
2016-10-07T18:50:20Z6144
2016-10-07T18:50:30Z7153

Query 1:

> SELECT mean("square"),"round" FROM "peg"
ERR: error parsing query: mixing aggregate and non-aggregate queries is not supported

The preceding statement includes an aggregate function and a standalone field.

The mean("square") function returns a single aggregated value, which is an average of the four values of square in the peg measurement. However, no single value can be returned for the four values of the round field that are not aggregated.

Query 2:

> SELECT mean("square"),"force" FROM "peg"
ERR: error parsing query: mixing aggregate and non-aggregate queries is not supported

The preceding statement includes an aggregate function and a standalone tag.

The mean("square") function returns a single aggregated value, which is an average of the four values of square in the peg measurement. However, no single value can be returned for the four values of the force tag that are not aggregated.

Deal with the "time and *influxql.VarRef are not compatible" error message

If date and time strings are enclosed in double quotation marks (") in a query, the time and *influxql.VarRef are not compatible error message is reported. You must use single quotation marks (') to enclose date and time strings.

Example

Enclose date and time strings in double quotation marks ('').

> SELECT "water_level" FROM "h2o_feet" WHERE "location"='santa_monica' AND time >="2015-08-18T00:00:00Z" AND time <="2015-08-18T00:12:00Z"
ERR: invalid operation: time and *influxql.VarRef are not compatible

Enclose date and time strings in single quotation marks (').

> SELECT "water_level" FROM "h2o_feet" WHERE "location"='santa_monica' AND time >='2015-08-18T00:00:00Z' AND time <='2015-08-18T00:12:00Z'

name: h2o_feet
time                   water_level
---------------
2015-08-18T00:00:00Z2.064
2015-08-18T00:06:00Z2.116
2015-08-18T00:12:00Z2.028

Deal with the "bad timestamp" error message

• Timestamp syntax

  If the line protocol includes a timestamp that is not in the UNIX format, the bad timestamp error message is reported.

  Example

  > INSERT pineapple value=1'2015-08-18T23:00:00Z'
  ERR:{"error":"unable to parse 'pineapple value=1 '2015-08-18T23:00:00Z'': bad timestamp"}

  In this example, the line protocol uses a timestamp in the RFC 3339 format. To prevent this error, change the timestamp to the UNIX format.

  > INSERT pineapple,fresh=true value=11439938800000000000

• Line protocol syntax

  If the line protocol includes general syntax errors, the bad timestamp error message is reported.

  Examples

  Write request 1:

  > INSERT hens location=2 value=9
  ERR:{"error":"unable to parse 'hens location=2 value=9': bad timestamp"}

  In the preceding statement, the line protocol separates the hen measurement from the location=2 tag by using a space instead of a comma (,). As a result, TSDB For InfluxDB® considers the value=9 field as a timestamp and returns the error message.

  To prevent this error, use a comma (,) to separate the measurement from the tag.

  > INSERT hens,location=2 value=9

  Write request 2:

  > INSERT cows,name=daisy milk_prod=3 happy=3
  ERR:{"error":"unable to parse 'cows,name=daisy milk_prod=3 happy=3': bad timestamp"}

  In the preceding statement, the line protocol separates the milk_prod=3 field from the happy=3 field by using a space instead of a comma (,). As a result, TSDB For InfluxDB® considers the happy=3 field as a timestamp and returns the error message.

  To prevent this error, use a comma (,) to separate the two fields.

  > INSERT cows,name=daisy milk_prod=3,happy=3

Deal with the "time outside range" error message

If the timestamp in the line protocol falls out of the valid time range of TSDB For InfluxDB®, the time outside range error message is reported.

The minimum valid timestamp is -9223372036854775806 or 1677-09-21T00:12:43.145224194Z. The maximum valid timestamp is 9223372036854775806 or 2262-04-11T23:47:16.854775806Z.

Deal with the "engine: cache maximum memory size exceeded" error message

If the cached memory size of the server exceeds the preset threshold in a short period of time, the engine: cache maximum memory size exceeded error message is reported. The preset threshold is determined by the instance type of your instance.