simple-redis-pool
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Simplistic node redis pool ready can scale with generic-pool support
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<h2><a href="index.html">Home</a></h2><h3>Classes</h3><ul><li><a href="RedisPool.html">RedisPool</a><ul class='methods'><li data-type='method'><a href="RedisPool.html#acquire">acquire</a></li><li data-type='method'><a href="RedisPool.html#availableCount">availableCount</a></li><li data-type='method'><a href="RedisPool.html#destroy">destroy</a></li><li data-type='method'><a href="RedisPool.html#drain">drain</a></li><li data-type='method'><a href="RedisPool.html#getName">getName</a></li><li data-type='method'><a href="RedisPool.html#getPoolOptions">getPoolOptions</a></li><li data-type='method'><a href="RedisPool.html#getPoolSize">getPoolSize</a></li><li data-type='method'><a href="RedisPool.html#getRedisOptions">getRedisOptions</a></li><li data-type='method'><a href="RedisPool.html#pendingCount">pendingCount</a></li><li data-type='method'><a href="RedisPool.html#release">release</a></li><li data-type='method'><a href="RedisPool.html#sendCommand">sendCommand</a></li><li data-type='method'><a href="RedisPool.html#status">status</a></li></ul></li></ul>
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<h1 class="page-title">redis_pool.js</h1>
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<pre class="prettyprint source linenums"><code>"use strict";
const genericPool = require("generic-pool");
const promisify = require("es6-promisify");
const retry = require("retry-as-promised");
const pick = require("lodash.pick");
const redis = require("redis");
const debug = require("debug")("simpleRedisPool");
const create = function (redisOptions) {
return new Promise((resolve, reject) => {
debug("Start redis createClient", redisOptions);
const client = redis.createClient(redisOptions);
client.on("error", err => {
debug("Failed redis createClient", err);
reject(err);
});
client.on("connect", () => {
debug("Succeeded redis createClient", redisOptions);
resolve(client);
});
});
};
const selectDB = function (client, db) {
return new Promise((resolve, reject) => {
client.select(db, function (err) {
if (err) reject(err);
debug("DB selected: ", db);
resolve(client);
});
});
};
/**
* @constructor
* @param {object} options - Accepts properties ["name", "redisOptions", "poolOptions", "logger"]
* @param {string} options.name - Name your pool
* @param {object} options.redisOptions - opts from [node_redis#options-object-properties]{@link https://github.com/NodeRedis/node_redis#options-object-properties}
* @param {object} options.poolOptions - opts from [node-pool#createpool]{@link https://github.com/coopernurse/node-pool#createpool}
* @param {object} options.logger - Inject your custom logger
*/
const RedisPool = module.exports = function (options) {
options = pick(options, ["name", "redisOptions", "poolOptions", "logger"]);
this.name = options.name || `redisPool-${Math.random().toString(36).substr(2, 10)}`;
this.redisOptions = options.redisOptions;
this.poolOptions = options.poolOptions;
this.logger = require("./logger")(options.logger);
const factory = {
create: () => {
// for retry
let createAttempts = 0;
// this is due to the limitation of node-pool ATM
// https://github.com/coopernurse/node-pool/issues/161#issuecomment-261109882
return retry(function () {
createAttempts++;
if (createAttempts > 3) {
const err = new Error("Failed redis createClient, " + JSON.stringify(options.redisOptions || {}));
err.name = "CONN_FAILED";
debug("Max conn createAttempts reached: %s, resolving to error:", createAttempts, err);
// reset for next try
createAttempts = 0;
return Promise.resolve(err);
}
return create(options.redisOptions);
}, {
max: 10,
name: "factory.create",
report: debug
});
},
destroy: (client) => {
return new Promise((resolve) => {
try {
// Flush when closing.
client.end(true, () => resolve());
debug("Client conn closed. Available count : %s. Pool size: %s", this.availableCount(), this.getPoolSize());
this.logger.log("Client conn closed. Available count : %s. Pool size: %s", this.availableCount(), this.getPoolSize());
} catch (err) {
debug("Failed to destroy connection", err);
this.logger.error("Failed to destroy connection", err);
// throw error cause infinite event loop; limitation of node-pool
// throw err;
}
});
}
};
// Now that the pool settings are ready create a pool instance.
debug("Creating pool", this.poolOptions);
this.pool = genericPool.createPool(factory, this.poolOptions);
this.pool.on("factoryCreateError", e => {
debug("Errored while connecting Redis", e);
this.logger.error("Errored while connecting Redis", e);
});
this.pool.on("factoryDestroyError", e => {
debug("Errored while destroying Redis conn", e);
this.logger.error("Errored while destroying Redis conn", e);
});
};
/**
* Send redis instructions
*
* @param {string} commandName - Name of the command
* @param {array} commandArgs - Args sent to the command
* @returns {promise} Promise resolve with the result or Error
*/
RedisPool.prototype.sendCommand = function (commandName, commandArgs) {
return this.pool.acquire()
.then(conn => {
commandArgs = [].concat(commandArgs || []);
debug("Executing send_command", commandName, commandArgs);
const sendCommand = promisify(conn.send_command, conn);
return (commandArgs.length > 0 ?
sendCommand(commandName, commandArgs) :
sendCommand(commandName)
)
.then(result => {
this.pool.release(conn);
return result;
})
.catch(err => {
this.pool.release(conn);
this.logger.error("Errored send_command", err);
debug("Errored send_command", err);
throw err;
});
});
};
/**
* Acquire a Redis connection and use an optional priority.
*
* @param {number} priority - priority list number
* @param {number} db - Use the db with range {0-16}
* @returns {promise} Promise resolve with the connection or Error
*/
RedisPool.prototype.acquire = function (priority, db) {
return this.pool.acquire(priority)
.then(client => {
if (client instanceof Error) {
debug("Couldn't acquire connection to %j", this.redisOptions);
this.logger.error("Couldn't acquire connection to %j", this.redisOptions);
throw client;
}
if (db) {
this.logger.info("select DB:", db);
return selectDB(client, db);
} else {
return client;
}
});
};
/**
* Release a Redis connection to the pool.
*
* @param {object} client - Redis connection
* @returns {promise} Promise
*/
RedisPool.prototype.release = function (client) {
return this.pool.release(client);
};
/**
* Destroy a Redis connection.
*
* @param {object} client - Redis connection
* @returns {promise} Promise
*/
RedisPool.prototype.destroy = function (client) {
return this.pool.destroy(client);
};
/**
* Drains the connection pool and call the callback id provided.
*
* @returns {promise} Promise
*/
RedisPool.prototype.drain = function () {
return this.pool.drain(() => this.pool.clear());
};
/**
* Returns factory.name for this pool
*
* @returns {string} Name of the pool
*/
RedisPool.prototype.getName = function () {
return this.name;
};
/**
* Returns this.redisOptions for this pool
*
* @returns {object} redis options given
*/
RedisPool.prototype.getRedisOptions = function () {
return this.redisOptions;
};
/**
* Returns this.poolOptions for this pool
*
* @returns {object} pool options given
*/
RedisPool.prototype.getPoolOptions = function () {
return this.poolOptions;
};
/**
* Returns size of the pool
*
* @returns {number} size of the pool
*/
RedisPool.prototype.getPoolSize = function () {
return this.pool.size;
};
/**
* Returns available connections count of the pool
*
* @returns {number} available connections count of the pool
*/
RedisPool.prototype.availableCount = function () {
return this.pool.available;
};
/**
* Returns pending connections count of the pool
*
* @returns {number} pending connections count of the pool
*/
RedisPool.prototype.pendingCount = function () {
return this.pool.pending;
};
/**
* Returns pool status and stats
*
* @returns {object} pool status and stats
*/
RedisPool.prototype.status = function () {
return {
name: this.name,
size: this.pool.size,
available: this.pool.available,
pending: this.pool.pending
};
};
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