ClickHouse/docs/en/operations/utils/clickhouse-benchmark.md

clickhouse-benchmark

Connects to a ClickHouse server and repeatedly sends specified queries.

Syntax:

$ echo "single query" | clickhouse-benchmark [keys]

or

$ clickhouse-benchmark [keys] <<< "single query"

If you want to send a set of queries, create a text file and place each query on the individual string in this file. For example:

SELECT * FROM system.numbers LIMIT 10000000
SELECT 1

Then pass this file to a standard input of clickhouse-benchmark.

clickhouse-benchmark [keys] < queries_file

Keys

• -c N, --concurrency=N — Number of queries that clickhouse-benchmark sends simultaneously. Default value: 1.
• -d N, --delay=N — Interval in seconds between intermediate reports (set 0 to disable reports). Default value: 1.
• -h WORD, --host=WORD — Server host. Default value: localhost. For the comparison mode you can use multiple -h keys.
• -p N, --port=N — Server port. Default value: 9000. For the comparison mode you can use multiple -p keys.
• -i N, --iterations=N — Total number of queries. Default value: 0.
• -r, --randomize — Random order of queries execution if there is more then one input query.
• -s, --secure — Using TLS connection.
• -t N, --timelimit=N — Time limit in seconds. clickhouse-benchmark stops sending queries when the specified time limit is reached. Default value: 0 (time limit disabled).
• --confidence=N — Level of confidence for T-test. Possible values: 0 (80%), 1 (90%), 2 (95%), 3 (98%), 4 (99%), 5 (99.5%). Default value: 5. In the comparison mode clickhouse-benchmark performs the Independent two-sample Student's t-test test to determine whether the two distributions aren't different with the selected level of confidence.
• --cumulative — Printing cumulative data instead of data per interval.
• --database=DATABASE_NAME — ClickHouse database name. Default value: default.
• --json=FILEPATH — JSON output. When the key is set, clickhouse-benchmark outputs a report to the specified JSON-file.
• --user=USERNAME — ClickHouse user name. Default value: default.
• --password=PSWD — ClickHouse user password. Default value: empty string.
• --stacktrace — Stack traces output. When the key is set, clickhouse-bencmark outputs stack traces of exceptions.
• --stage=WORD — Query processing stage at server. ClickHouse stops query processing and returns answer to clickhouse-benchmark at the specified stage. Possible values: complete, fetch_columns, with_mergeable_state. Default value: complete.
• --help — Shows the help message.

If you want to apply some settings for queries, pass them as a key --<session setting name>= SETTING_VALUE. For example, --max_memory_usage=1048576.

Output

By default, clickhouse-benchmark reports for each --delay interval.

Example of the report:

Queries executed: 10.

localhost:9000, queries 10, QPS: 6.772, RPS: 67904487.440, MiB/s: 518.070, result RPS: 67721584.984, result MiB/s: 516.675.

0.000%		0.145 sec.	
10.000%		0.146 sec.	
20.000%		0.146 sec.	
30.000%		0.146 sec.	
40.000%		0.147 sec.	
50.000%		0.148 sec.	
60.000%		0.148 sec.	
70.000%		0.148 sec.	
80.000%		0.149 sec.	
90.000%		0.150 sec.	
95.000%		0.150 sec.	
99.000%		0.150 sec.	
99.900%		0.150 sec.	
99.990%		0.150 sec.	

In the report you can find:

• Number of queries in the Queries executed: field.

• Status string containing (in order):

  • Endpoint of ClickHouse server.
  • Number of processed queries.
  • QPS: QPS: How many queries server performed per second during a period specified in the --delay argument.
  • RPS: How many rows server read per second during a period specified in the --delay argument.
  • MiB/s: How many mebibytes server read per second during a period specified in the --delay argument.
  • result RPS: How many rows placed by server to the result of a query per second during a period specified in the --delay argument.
  • result MiB/s. How many mebibytes placed by server to the result of a query per second during a period specified in the --delay argument.

• Percentiles of queries execution time.

Comparison mode

clickhouse-benchmark can compare performances for two running ClickHouse servers.

To use the comparison mode, specify endpoints of both servers by two pairs of --host, --port keys. Keys matched together by position in arguments list, the first --host is matched with the first --port and so on. clickhouse-benchmark establishes connections to both servers, then sends queries. Each query addressed to a randomly selected server. The results are shown for each server separately.

Example

$ echo "SELECT * FROM system.numbers LIMIT 10000000 OFFSET 10000000" | clickhouse-benchmark -i 10

Loaded 1 queries.

Queries executed: 6.

localhost:9000, queries 6, QPS: 6.153, RPS: 123398340.957, MiB/s: 941.455, result RPS: 61532982.200, result MiB/s: 469.459.

0.000%		0.159 sec.	
10.000%		0.159 sec.	
20.000%		0.159 sec.	
30.000%		0.160 sec.	
40.000%		0.160 sec.	
50.000%		0.162 sec.	
60.000%		0.164 sec.	
70.000%		0.165 sec.	
80.000%		0.166 sec.	
90.000%		0.166 sec.	
95.000%		0.167 sec.	
99.000%		0.167 sec.	
99.900%		0.167 sec.	
99.990%		0.167 sec.	



Queries executed: 10.

localhost:9000, queries 10, QPS: 6.082, RPS: 121959604.568, MiB/s: 930.478, result RPS: 60815551.642, result MiB/s: 463.986.

0.000%		0.159 sec.	
10.000%		0.159 sec.	
20.000%		0.160 sec.	
30.000%		0.163 sec.	
40.000%		0.164 sec.	
50.000%		0.165 sec.	
60.000%		0.166 sec.	
70.000%		0.166 sec.	
80.000%		0.167 sec.	
90.000%		0.167 sec.	
95.000%		0.170 sec.	
99.000%		0.172 sec.	
99.900%		0.172 sec.	
99.990%		0.172 sec.