feat(client): add latency histogram (#3099)

* add latency histogram command, tests (##1955)

Author: NaughtySora

packages/client/lib/commands/LATENCY_HISTOGRAM.spec.ts

@@ -0,0 +1,93 @@
+import assert from "node:assert/strict";
+import testUtils, { GLOBAL } from "../test-utils";
+import LATENCY_HISTOGRAM from "./LATENCY_HISTOGRAM";
+import { parseArgs } from "./generic-transformers";
+
+describe("LATENCY HISTOGRAM", () => {
+ describe("transformArguments", () => {
+ it("filtered by command set", () => {
+ assert.deepEqual(parseArgs(LATENCY_HISTOGRAM, "set"), [
+ "LATENCY",
+ "HISTOGRAM",
+ "set",
+ ]);
+ });
+
+ it("unfiltered", () => {
+ assert.deepEqual(parseArgs(LATENCY_HISTOGRAM), [
+ "LATENCY",
+ "HISTOGRAM",
+ ]);
+ });
+ });
+
+ describe("RESP 2", () => {
+ testUtils.testWithClient(
+ "unfiltered list",
+ async (client) => {
+ await client.configResetStat();
+ await Promise.all([
+ client.lPush("push-key", "hello "),
+ client.set("set-key", "world!"),
+ ]);
+ const histogram = await client.latencyHistogram();
+ const commands = ["config|resetstat", "set", "lpush"];
+ for (const command of commands) {
+ assert.ok(typeof histogram[command]["calls"], "number");
+ }
+ },
+ GLOBAL.SERVERS.OPEN,
+ );
+
+ testUtils.testWithClient(
+ "filtered by a command list",
+ async (client) => {
+ await client.configSet("latency-monitor-threshold", "100");
+ await client.set("set-key", "hello");
+ const histogram = await client.latencyHistogram("set");
+ assert.ok(typeof histogram.set["calls"], "number");
+ },
+ GLOBAL.SERVERS.OPEN,
+ );
+ });
+
+ describe("RESP 3", () => {
+ testUtils.testWithClient(
+ "unfiltered list",
+ async (client) => {
+ await client.configResetStat();
+ await Promise.all([
+ client.lPush("push-key", "hello "),
+ client.set("set-key", "world!"),
+ ]);
+ const histogram = await client.latencyHistogram();
+ const commands = ["config|resetstat", "set", "lpush"];
+ for (const command of commands) {
+ assert.ok(typeof histogram[command]["calls"], "number");
+ }
+ },
+ {
+ ...GLOBAL.SERVERS.OPEN,
+ clientOptions: {
+ RESP: 3,
+ },
+ },
+ );
+
+ testUtils.testWithClient(
+ "filtered by a command list",
+ async (client) => {
+ await client.configSet("latency-monitor-threshold", "100");
+ await client.set("set-key", "hello");
+ const histogram = await client.latencyHistogram("set");
+ assert.ok(typeof histogram.set["calls"], "number");
+ },
+ {
+ ...GLOBAL.SERVERS.OPEN,
+ clientOptions: {
+ RESP: 3,
+ },
+ },
+ );
+ });
+});

packages/client/lib/commands/LATENCY_HISTOGRAM.ts

@@ -0,0 +1,46 @@
+import { CommandParser } from '../client/parser';
+import { Command } from '../RESP/types';
+import { transformTuplesToMap } from './generic-transformers';
+
+type RawHistogram = [string, number, string, number[]];
+
+type Histogram = Record<string, {
+ calls: number;
+ histogram_usec: Record<string, number>;
+}>;
+
+const id = (n: number) => n;
+
+export default {
+ CACHEABLE: false,
+ IS_READ_ONLY: true,
+ /**
+ * Constructs the LATENCY HISTOGRAM command
+ *
+ * @param parser - The command parser
+ * @param commands - The list of redis commands to get histogram for
+ * @see https://redis.io/docs/latest/commands/latency-histogram/
+ */
+ parseCommand(parser: CommandParser, ...commands: string[]) {
+ const args = ['LATENCY', 'HISTOGRAM'];
+ if (commands.length !== 0) {
+ args.push(...commands);
+ }
+ parser.push(...args);
+ },
+ transformReply: {
+ 2: (reply: (string | RawHistogram)[]): Histogram => {
+ const result: Histogram = {};
+ if (reply.length === 0) return result;
+ for (let i = 1; i < reply.length; i += 2) {
+ const histogram = reply[i] as RawHistogram;
+ result[reply[i - 1] as string] = {
+ calls: histogram[1],
+ histogram_usec: transformTuplesToMap(histogram[3], id),
+ };
+ }
+ return result;
+ },
+ 3: undefined as unknown as () => Histogram,
+ }
+} as const satisfies Command;

packages/client/lib/commands/index.ts

@@ -364,6 +364,7 @@ import VREM from './VREM';
 import VSETATTR from './VSETATTR';
 import VSIM from './VSIM';
 import VSIM_WITHSCORES from './VSIM_WITHSCORES';
+import LATENCY_HISTOGRAM from './LATENCY_HISTOGRAM';
 
 export {
  CLIENT_KILL_FILTERS,
@@ -722,6 +723,8 @@ export default {
  latencyGraph: LATENCY_GRAPH,
  LATENCY_HISTORY,
  latencyHistory: LATENCY_HISTORY,
+ LATENCY_HISTOGRAM,
+ latencyHistogram: LATENCY_HISTOGRAM,
  LATENCY_LATEST,
  latencyLatest: LATENCY_LATEST,
  LATENCY_RESET,