Key-Value load

A simple load type using a YDB database as a Key-Value storage.

Types of load

This load test runs 3 types of load:

  • upsert: Using the UPSERT operation, inserts rows that are tuples (key, value1, value2, ... valueN) into the table created previously with the init command, the N number is specified in the settings.
  • insert: The function is the same as the upsert load, only the INSERT operation is used for insertion.
  • select: Reads data using the SELECT * WHERE key = $key operation. A query always affects all table columns, but isn't always a point query, and the number of primary key variations can be controlled using parameters.

Load test initialization

To get started, you must create tables. When creating them, you can specify how many rows to insert during initialization:

ydb workload kv init [init options...]

View a description of the command to initialize the table:

ydb workload kv init --help

Available parameters

Parameter name Parameter description
--init-upserts <value> Number of insertion operations to be performed during initialization. Default: 1000.
--min-partitions Minimum number of shards for tables. Default: 40.
--auto-partition Enabling/disabling auto-sharding. Possible values: 0 or 1. Default: 1.
--max-first-key Maximum value of the primary key of the table. Default: 264—12^{64} — 1.
--len The size of the rows in bytes that are inserted into the table as values. Default: 8.
--cols Number of columns in the table. Default: 2 counting Key.
--rows Number of affected rows in one query. Default: 1.

The following command is used to create a table:

CREATE TABLE `kv_test`(
    c0 Uint64,
    c1 String,
    c2 String,
    ...
    cN String,
    PRIMARY KEY(c0)) WITH (
        AUTO_PARTITIONING_BY_LOAD = ENABLED,
        AUTO_PARTITIONING_MIN_PARTITIONS_COUNT = partsNum,
        UNIFORM_PARTITIONS = partsNum,
        AUTO_PARTITIONING_MAX_PARTITIONS_COUNT = 1000
    )
)

Examples of load initialization

Example of a command to create a table with 1000 rows:

ydb workload kv init --init-upserts 1000

Deleting a table

When the work is complete, you can delete the table:

ydb workload kv clean

The following YQL command is executed:

DROP TABLE `kv_test`

Examples of using clean

ydb workload kv clean

Running a load test

To run the load, execute the command:

ydb workload kv run [workload type...] [global workload options...] [specific workload options...]

During this test, workload statistics for each time window are displayed on the screen.

See the description of the command to run the data load:

ydb workload kv run --help

Global parameters for all types of load

Parameter name Short name Parameter description
--seconds <value> -s <value> Duration of the test, in seconds. Default: 10.
--threads <value> -t <value> The number of parallel threads creating the load. Default: 10.
--quiet - Outputs only the final test result.
--print-timestamp - Print the time together with the statistics of each time window.
--client-timeout - Transport timeout in milliseconds.
--operation-timeout - Operation timeout in milliseconds.
--cancel-after - Timeout for canceling an operation in milliseconds.
--window - Statistics collection window in seconds. Default: 1.
--max-first-key - Maximum value of the primary key of the table. Default: 264−12^{64} - 1.
--cols - Number of columns in the table. Default: 2 counting Key.
--rows - Number of affected rows in one query. Default: 1.

Upsert load

This load type inserts tuples (key, value1, value2, ..., valueN)

YQL query:

DECLARE r0 AS Uint64
DECLARE c00 AS String;
DECLARE c01 AS String;
...
DECLARE c0{N - 1} AS String;
DECLARE r1 AS Uint64
DECLARE c10 AS String;
DECLARE c11 AS String;
...
DECLARE c1{N - 1} AS String;
UPSERT INTO `kv_test`(c0, c1, ... cN) VALUES ( (r0, c00, ... c0{N - 1}), (r1, c10, ... c1{N - 1}), ... )

To run this type of load, execute the command:

ydb workload kv run upsert [global workload options...] [specific workload options...]

Parameters for upsert

Parameter name Parameter description
--len The size of the rows in bytes that are inserted into the table as values. Default: 8.

Insert load

This load type inserts tuples (key, value1, value2, ..., valueN)

YQL query:

DECLARE r0 AS Uint64
DECLARE c00 AS String;
DECLARE c01 AS String;
...
DECLARE c0{N - 1} AS String;
DECLARE r1 AS Uint64
DECLARE c10 AS String;
DECLARE c11 AS String;
...
DECLARE c1{N - 1} AS String;
INSERT INTO `kv_test`(c0, c1, ... cN) VALUES ( (r0, c00, ... c0{N - 1}), (r1, c10, ... c1{N - 1}), ... )

To run this type of load, execute the command:

ydb workload kv run insert [global workload options...] [specific workload options...]

Parameters for insert

Parameter name Parameter description
--len The size of the rows in bytes that are inserted into the table as values. Default: 8.

Select load

This type of load creates SELECT queries that return rows based on an exact match of the primary key.

YQL query:

DECLARE r0 AS Uint64
DECLARE r1 AS Uint64
...
DECLARE rM AS Uint64
SELECT * FROM `kv_test`(c0, c1, ..., cN) WHERE (
    c0 == r0 OR
    c0 == r1 OR
    ...
    c0 == rM
)

To run this type of load, execute the command:

ydb workload kv run select [global workload options...]
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