feat(sap): use the native driver for connection pooling (#11520)

* feat(sap): use the native driver for connection pooling * Add pool error handler
2025-12-08 21:26:23 +00:00 · 2025-07-01 23:43:12 +02:00 · 2025-07-01 23:43:12 +02:00 · aebc7ebc67
commit aebc7ebc67
parent 5904ac3db2
12 changed files with 278 additions and 178 deletions
--- a/README-zh_CN.md
+++ b/README-zh_CN.md
@ -203,9 +203,7 @@ await timber.remove()
    - **SAP Hana**

        ```
-        npm config set @sap:registry https://npm.sap.com
        npm i @sap/hana-client
-        npm i hdb-pool
        ```

 ##### TypeScript 配置
--- a/README.md
+++ b/README.md
@ -215,11 +215,8 @@ await timber.remove()

        ```
        npm install @sap/hana-client
-        npm install hdb-pool
        ```

-        _SAP Hana support made possible by the sponsorship of [Neptune Software](https://www.neptune-software.com/)._
-
    - for **Google Cloud Spanner**

        ```
--- a/README_ko.md
+++ b/README_ko.md
@ -176,11 +176,8 @@ await timber.remove()

        ```
        npm i @sap/hana-client
-        npm i hdb-pool
        ```

-        _[Neptune Software](https://www.neptune-software.com/)의 후원으로 SAP Hana 지원이 가능해졌다._
-
    - **MongoDB** (experimental)의 경우

        `npm install mongodb@^5.2.0 --save`
--- a/docs/docs/data-source/2-data-source-options.md
+++ b/docs/docs/data-source/2-data-source-options.md
@ -544,6 +544,24 @@ The following TNS connection string will be used in the next explanations:
 -   `sid` - The System Identifier (SID) identifies a specific database instance. For example, "sales".
 -   `serviceName` - The Service Name is an identifier of a database service. For example, `sales.us.example.com`.

+## `sap` data source options
+
+-   `host` - The hostname of the SAP HANA server. For example, `"localhost"`.
+-   `port` - The port number of the SAP HANA server. For example, `30015`.
+-   `username` - The username to connect to the SAP HANA server. For example, `"SYSTEM"`.
+-   `password` - The password to connect to the SAP HANA server. For example, `"password"`.
+-   `database` - The name of the database to connect to. For example, `"HXE"`.
+-   `encrypt` - Whether to encrypt the connection. For example, `true`.
+-   `sslValidateCertificate` - Whether to validate the SSL certificate. For example, `true`.
+-   `key`, `cert` and `ca` - Private key, public certificate and certificate authority for the encrypted connection.
+-   `pool` — Connection pool configuration object:
+    -   `maxConnectedOrPooled` (number) — Max active or idle connections in the pool (default: 10).
+    -   `maxPooledIdleTime` (seconds) — Time before an idle connection is closed (default: 30).
+    -   `pingCheck` (boolean) — Whether to validate connections before use (default: false).
+    -   `poolCapacity` (number) — Maximum number of connections to be kept available (default: no limit).
+
+See the official documentation of SAP HANA Client for more details as well as the `extra` properties: [Node.js Connection Properties](https://help.sap.com/docs/SAP_HANA_CLIENT/f1b440ded6144a54ada97ff95dac7adf/4fe9978ebac44f35b9369ef5a4a26f4c.html).
+
 ## Data Source Options example

 Here is a small example of data source options for mysql:
--- a/docs/docs/getting-started.md
+++ b/docs/docs/getting-started.md
@ -193,18 +193,11 @@ await timber.remove()

    - for **SAP Hana**

-        ```
-        npm install @sap/hana-client
-        npm install hdb-pool
-        ```
-
-        _SAP Hana support made possible by the sponsorship of [Neptune Software](https://www.neptune-software.com/)._
+        `npm install @sap/hana-client --save`

    - for **Google Cloud Spanner**

-        ```
-        npm install @google-cloud/spanner --save
-        ```
+        `npm install @google-cloud/spanner --save`

        Provide authentication credentials to your application code
        by setting the environment variable `GOOGLE_APPLICATION_CREDENTIALS`:
--- a/package-lock.json
+++ b/package-lock.json
@ -58,7 +58,6 @@
        "gulp-sourcemaps": "^3.0.0",
        "gulp-typescript": "^6.0.0-alpha.1",
        "gulpclass": "^0.2.0",
-        "hdb-pool": "^0.1.6",
        "husky": "^9.1.7",
        "lint-staged": "^15.5.2",
        "mocha": "^10.8.2",
@ -95,9 +94,8 @@
      },
      "peerDependencies": {
        "@google-cloud/spanner": "^5.18.0 || ^6.0.0 || ^7.0.0",
-        "@sap/hana-client": "^2.12.25",
+        "@sap/hana-client": "^2.14.22",
        "better-sqlite3": "^8.0.0 || ^9.0.0 || ^10.0.0 || ^11.0.0",
-        "hdb-pool": "^0.1.6",
        "ioredis": "^5.0.4",
        "mongodb": "^5.8.0 || ^6.0.0",
        "mssql": "^9.1.1 || ^10.0.1 || ^11.0.1",
@ -123,9 +121,6 @@
        "better-sqlite3": {
          "optional": true
        },
-        "hdb-pool": {
-          "optional": true
-        },
        "ioredis": {
          "optional": true
        },
@ -8384,17 +8379,6 @@
        "node": ">= 0.4"
      }
    },
-    "node_modules/hdb-pool": {
-      "version": "0.1.6",
-      "resolved": "https://registry.npmjs.org/hdb-pool/-/hdb-pool-0.1.6.tgz",
-      "integrity": "sha512-8VZOLn1EHamm1NmTFQj2iqjVcfonYIsD7F5DU2bz2N+gF+knp6/MbAVeRXkJtya717IBkPeA5iv0/1iPuYo4ZA==",
-      "deprecated": "Package no longer supported. Contact Support at https://www.npmjs.com/support for more info.",
-      "dev": true,
-      "license": "MIT",
-      "engines": {
-        "node": ">= 8"
-      }
-    },
    "node_modules/he": {
      "version": "1.2.0",
      "resolved": "https://registry.npmjs.org/he/-/he-1.2.0.tgz",
--- a/package.json
+++ b/package.json
@ -136,7 +136,6 @@
    "gulp-sourcemaps": "^3.0.0",
    "gulp-typescript": "^6.0.0-alpha.1",
    "gulpclass": "^0.2.0",
-    "hdb-pool": "^0.1.6",
    "husky": "^9.1.7",
    "lint-staged": "^15.5.2",
    "mocha": "^10.8.2",
@ -167,9 +166,8 @@
  },
  "peerDependencies": {
    "@google-cloud/spanner": "^5.18.0 || ^6.0.0 || ^7.0.0",
-    "@sap/hana-client": "^2.12.25",
+    "@sap/hana-client": "^2.14.22",
    "better-sqlite3": "^8.0.0 || ^9.0.0 || ^10.0.0 || ^11.0.0",
-    "hdb-pool": "^0.1.6",
    "ioredis": "^5.0.4",
    "mongodb": "^5.8.0 || ^6.0.0",
    "mssql": "^9.1.1 || ^10.0.1 || ^11.0.1",
@ -195,9 +193,6 @@
    "better-sqlite3": {
      "optional": true
    },
-    "hdb-pool": {
-      "optional": true
-    },
    "ioredis": {
      "optional": true
    },
--- a/src/driver/sap/SapConnectionOptions.ts
+++ b/src/driver/sap/SapConnectionOptions.ts
@ -19,13 +19,12 @@ export interface SapConnectionOptions

    /**
     * The driver objects
-     * This defaults to require("hdb-pool")
+     * This defaults to require("@sap/hana-client")
     */
    readonly driver?: any

    /**
-     * The driver objects
-     * This defaults to require("@sap/hana-client")
+     * @deprecated Use {@link driver} instead.
     */
    readonly hanaClientDriver?: any

@ -33,30 +32,64 @@ export interface SapConnectionOptions
     * Pool options.
     */
    readonly pool?: {
+        /**
+         * Maximum number of open connections created by the pool, each of which
+         * may be in the pool waiting to be reused or may no longer be in the
+         * pool and actively being used (default: 10).
+         */
+        readonly maxConnectedOrPooled?: number
+
+        /**
+         * Defines the maximum time, in seconds, that connections are allowed to
+         * remain in the pool before being marked for eviction (default: 30).
+         */
+        readonly maxPooledIdleTime?: number
+
+        /**
+         * Determines whether or not the pooled connection should be tested for
+         * viability before being reused (default: false).
+         */
+        readonly pingCheck?: boolean
+
+        /**
+         * Maximum number of connections allowed to be in the pool, waiting to
+         * be reused (default: 0, no limit).
+         */
+        readonly poolCapacity?: number
+
        /**
         * Max number of connections.
+         * @deprecated Use {@link maxConnectedOrPooled} instead.
         */
        readonly max?: number

        /**
         * Minimum number of connections.
+         * @deprecated Obsolete, no alternative exists.
         */
        readonly min?: number

        /**
-         * Maximum number of waiting requests allowed. (default=0, no limit).
+         * Maximum number of waiting requests allowed.
+         * @deprecated Obsolete, no alternative exists.
         */
        readonly maxWaitingRequests?: number
+
        /**
-         * Max milliseconds a request will wait for a resource before timing out. (default=5000)
+         * Max milliseconds a request will wait for a resource before timing out.
+         * @deprecated Obsolete, no alternative exists.
         */
        readonly requestTimeout?: number
+
        /**
-         * How often to run resource timeout checks. (default=0, disabled)
+         * How often to run resource timeout checks.
+         * @deprecated Obsolete, no alternative exists.
         */
        readonly checkInterval?: number
+
        /**
-         * Idle timeout
+         * Idle timeout (in milliseconds).
+         * @deprecated Use {@link maxPooledIdleTime} (in seconds) instead .
         */
        readonly idleTimeout?: number

@ -66,6 +99,4 @@ export interface SapConnectionOptions
         */
        readonly poolErrorHandler?: (err: any) => any
    }
-
-    readonly poolSize?: never
 }
--- a/src/driver/sap/SapDriver.ts
+++ b/src/driver/sap/SapDriver.ts
@ -1,3 +1,4 @@
+import { promisify } from "node:util"
 import {
    ColumnType,
    ConnectionIsNotSetError,
@ -13,21 +14,20 @@ import { TypeORMError } from "../../error/TypeORMError"
 import { ColumnMetadata } from "../../metadata/ColumnMetadata"
 import { PlatformTools } from "../../platform/PlatformTools"
 import { RdbmsSchemaBuilder } from "../../schema-builder/RdbmsSchemaBuilder"
+import { View } from "../../schema-builder/view/View"
 import { ApplyValueTransformers } from "../../util/ApplyValueTransformers"
 import { DateUtils } from "../../util/DateUtils"
+import { InstanceChecker } from "../../util/InstanceChecker"
 import { OrmUtils } from "../../util/OrmUtils"
 import { Driver } from "../Driver"
+import { DriverUtils } from "../DriverUtils"
 import { CteCapabilities } from "../types/CteCapabilities"
 import { DataTypeDefaults } from "../types/DataTypeDefaults"
 import { MappedColumnTypes } from "../types/MappedColumnTypes"
+import { ReplicationMode } from "../types/ReplicationMode"
+import { UpsertType } from "../types/UpsertType"
 import { SapConnectionOptions } from "./SapConnectionOptions"
 import { SapQueryRunner } from "./SapQueryRunner"
-import { ReplicationMode } from "../types/ReplicationMode"
-import { DriverUtils } from "../DriverUtils"
-import { View } from "../../schema-builder/view/View"
-import { InstanceChecker } from "../../util/InstanceChecker"
-import { UpsertType } from "../types/UpsertType"
-
 /**
 * Organizes communication with SAP Hana DBMS.
 *
@ -44,24 +44,24 @@ export class SapDriver implements Driver {
    connection: DataSource

    /**
-     * Hana Pool instance.
+     * SAP HANA Client Pool instance.
     */
    client: any

    /**
-     * Hana Client streaming extension.
+     * SAP HANA Client streaming extension.
     */
    streamClient: any
+
    /**
     * Pool for master database.
     */
    master: any

    /**
-     * Pool for slave databases.
-     * Used in replication.
+     * Function handling errors thrown by drivers pool.
     */
-    slaves: any[] = []
+    poolErrorHandler: (error: any) => void

    // -------------------------------------------------------------------------
    // Public Implemented Properties
@ -225,7 +225,7 @@ export class SapDriver implements Driver {

    /**
     * Max length allowed by SAP HANA for aliases (identifiers).
-     * @see https://help.sap.com/viewer/4fe29514fd584807ac9f2a04f6754767/2.0.03/en-US/20a760537519101497e3cfe07b348f3c.html
+     * @see https://help.sap.com/docs/hana-cloud-database/sap-hana-cloud-sap-hana-database-sql-reference-guide/system-limitations
     */
    maxAliasLength = 128

@ -259,54 +259,62 @@ export class SapDriver implements Driver {
     */
    async connect(): Promise<void> {
        // HANA connection info
-        const dbParams = {
-            hostName: this.options.host,
+        const connectionOptions: any = {
+            host: this.options.host,
            port: this.options.port,
-            userName: this.options.username,
+            user: this.options.username,
            password: this.options.password,
-            ...this.options.extra,
+            database: this.options.database,
+            currentSchema: this.options.schema,
+            encrypt: this.options.encrypt,
+            sslValidateCertificate: this.options.sslValidateCertificate,
+            key: this.options.key,
+            cert: this.options.cert,
+            ca: this.options.ca,
        }
-
-        if (this.options.database) dbParams.databaseName = this.options.database
-        if (this.options.schema) dbParams.currentSchema = this.options.schema
-        if (this.options.encrypt) dbParams.encrypt = this.options.encrypt
-        if (this.options.sslValidateCertificate)
-            dbParams.validateCertificate = this.options.sslValidateCertificate
-        if (this.options.key) dbParams.key = this.options.key
-        if (this.options.cert) dbParams.cert = this.options.cert
-        if (this.options.ca) dbParams.ca = this.options.ca
+        Object.keys(connectionOptions).forEach((key) => {
+            if (connectionOptions[key] === undefined) {
+                delete connectionOptions[key]
+            }
+        })
+        Object.assign(connectionOptions, this.options.extra ?? {})

        // pool options
-        const options: any = {
-            min:
-                this.options.pool && this.options.pool.min
-                    ? this.options.pool.min
-                    : 1,
-            max:
-                this.options.pool && this.options.pool.max
-                    ? this.options.pool.max
-                    : 10,
+        const poolOptions: any = {
+            maxConnectedOrPooled:
+                this.options.pool?.maxConnectedOrPooled ??
+                this.options.pool?.max ??
+                this.options.poolSize ??
+                10,
+            maxPooledIdleTime:
+                this.options.pool?.maxPooledIdleTime ??
+                (this.options.pool?.idleTimeout
+                    ? this.options.pool.idleTimeout / 1000
+                    : 30),
+        }
+        if (this.options.pool?.pingCheck) {
+            poolOptions.pingCheck = this.options.pool.pingCheck
+        }
+        if (this.options.pool?.poolCapacity) {
+            poolOptions.poolCapacity = this.options.pool.poolCapacity
        }

-        if (this.options.pool && this.options.pool.checkInterval)
-            options.checkInterval = this.options.pool.checkInterval
-        if (this.options.pool && this.options.pool.maxWaitingRequests)
-            options.maxWaitingRequests = this.options.pool.maxWaitingRequests
-        if (this.options.pool && this.options.pool.requestTimeout)
-            options.requestTimeout = this.options.pool.requestTimeout
-        if (this.options.pool && this.options.pool.idleTimeout)
-            options.idleTimeout = this.options.pool.idleTimeout
-
-        const { logger } = this.connection
-
-        const poolErrorHandler =
-            options.poolErrorHandler ||
-            ((error: any) =>
-                logger.log("warn", `SAP Hana pool raised an error. ${error}`))
-        this.client.eventEmitter.on("poolError", poolErrorHandler)
+        this.poolErrorHandler =
+            this.options.pool?.poolErrorHandler ??
+            ((error: Error) => {
+                this.connection.logger.log(
+                    "warn",
+                    `SAP HANA pool raised an error: ${error}`,
+                )
+            })

        // create the pool
-        this.master = this.client.createPool(dbParams, options)
+        try {
+            this.master = this.client.createPool(connectionOptions, poolOptions)
+        } catch (error) {
+            this.poolErrorHandler(error)
+            throw error
+        }

        const queryRunner = this.createQueryRunner("master")

@ -338,7 +346,40 @@ export class SapDriver implements Driver {
        }

        this.master = undefined
-        await pool.clear()
+        try {
+            await promisify(pool.clear).call(pool)
+        } catch (error) {
+            this.poolErrorHandler(error)
+            throw error
+        }
+    }
+
+    /**
+     * Obtains a new database connection to a master server.
+     * Used for replication.
+     * If replication is not setup then returns default connection's database connection.
+     */
+    async obtainMasterConnection(): Promise<any> {
+        const pool = this.master
+        if (!pool) {
+            throw new TypeORMError("Driver not Connected")
+        }
+
+        try {
+            return await promisify(pool.getConnection).call(pool)
+        } catch (error) {
+            this.poolErrorHandler(error)
+            throw error
+        }
+    }
+
+    /**
+     * Obtains a new database connection to a slave server.
+     * Used for replication.
+     * If replication is not setup then returns master (default) connection's database connection.
+     */
+    async obtainSlaveConnection(): Promise<any> {
+        return this.obtainMasterConnection()
    }

    /**
@ -724,28 +765,6 @@ export class SapDriver implements Driver {
        return type
    }

-    /**
-     * Obtains a new database connection to a master server.
-     * Used for replication.
-     * If replication is not setup then returns default connection's database connection.
-     */
-    obtainMasterConnection(): Promise<any> {
-        if (!this.master) {
-            throw new TypeORMError("Driver not Connected")
-        }
-
-        return this.master.getConnection()
-    }
-
-    /**
-     * Obtains a new database connection to a slave server.
-     * Used for replication.
-     * If replication is not setup then returns master (default) connection's database connection.
-     */
-    obtainSlaveConnection(): Promise<any> {
-        return this.obtainMasterConnection()
-    }
-
    /**
     * Creates generated map of values generated or returned by database after INSERT query.
     */
@ -851,22 +870,19 @@ export class SapDriver implements Driver {
     * If driver dependency is not given explicitly, then try to load it via "require".
     */
    protected loadDependencies(): void {
-        try {
-            const client = this.options.driver || PlatformTools.load("hdb-pool")
+        const client = this.options.driver ?? this.options.hanaClientDriver
+        if (client) {
            this.client = client
-        } catch (e) {
-            // todo: better error for browser env
-            throw new DriverPackageNotInstalledError("SAP Hana", "hdb-pool")
+
+            return
        }

        try {
-            if (!this.options.hanaClientDriver) {
-                PlatformTools.load("@sap/hana-client")
-                this.streamClient = PlatformTools.load(
-                    "@sap/hana-client/extension/Stream",
-                )
-            }
-        } catch (e) {
+            this.client = PlatformTools.load("@sap/hana-client")
+            this.streamClient = PlatformTools.load(
+                "@sap/hana-client/extension/Stream",
+            )
+        } catch {
            // todo: better error for browser env
            throw new DriverPackageNotInstalledError(
                "SAP Hana",
--- a/src/driver/sap/SapQueryRunner.ts
+++ b/src/driver/sap/SapQueryRunner.ts
@ -1,4 +1,4 @@
-import { promisify } from "util"
+import { promisify } from "node:util"
 import { ObjectLiteral } from "../../common/ObjectLiteral"
 import { QueryFailedError, TypeORMError } from "../../error"
 import { QueryRunnerAlreadyReleasedError } from "../../error/QueryRunnerAlreadyReleasedError"
@ -85,14 +85,20 @@ export class SapQueryRunner extends BaseQueryRunner implements QueryRunner {
     * Releases used database connection.
     * You cannot use query runner methods once its released.
     */
-    release(): Promise<void> {
+    async release(): Promise<void> {
        this.isReleased = true

        if (this.databaseConnection) {
-            return this.driver.master.release(this.databaseConnection)
+            // return the connection back to the pool
+            try {
+                await promisify(this.databaseConnection.disconnect).call(
+                    this.databaseConnection,
+                )
+            } catch (error) {
+                this.driver.poolErrorHandler(error)
+                throw error
+            }
        }
-
-        return Promise.resolve()
    }

    /**
@ -168,14 +174,12 @@ export class SapQueryRunner extends BaseQueryRunner implements QueryRunner {
     */
    async setAutoCommit(options: { status: "on" | "off" }) {
        const connection = await this.connect()
-
-        const execute = promisify(connection.exec.bind(connection))
-
        connection.setAutoCommit(options.status === "on")

-        const query = `SET TRANSACTION AUTOCOMMIT DDL ${options.status.toUpperCase()};`
+        const query = `SET TRANSACTION AUTOCOMMIT DDL ${options.status.toUpperCase()}`
+        this.driver.connection.logger.logQuery(query, [], this)
        try {
-            await execute(query)
+            await promisify(connection.exec).call(connection, query)
        } catch (error) {
            throw new QueryFailedError(query, [], error)
        }
@ -270,26 +274,20 @@ export class SapQueryRunner extends BaseQueryRunner implements QueryRunner {
            if (isInsertQuery) {
                const lastIdQuery = `SELECT CURRENT_IDENTITY_VALUE() FROM "SYS"."DUMMY"`
                this.driver.connection.logger.logQuery(lastIdQuery, [], this)
-                const identityValueResult = await new Promise<any>(
-                    (ok, fail) => {
-                        databaseConnection.exec(
-                            lastIdQuery,
-                            (err: any, raw: any) =>
-                                err
-                                    ? fail(
-                                          new QueryFailedError(
-                                              lastIdQuery,
-                                              [],
-                                              err,
-                                          ),
-                                      )
-                                    : ok(raw),
-                        )
-                    },
-                )
+                try {
+                    const identityValueResult: [
+                        { "CURRENT_IDENTITY_VALUE()": unknown },
+                    ] = await promisify(databaseConnection.exec).call(
+                        databaseConnection,
+                        lastIdQuery,
+                    )

-                result.raw = identityValueResult[0]["CURRENT_IDENTITY_VALUE()"]
-                result.records = identityValueResult
+                    result.raw =
+                        identityValueResult[0]["CURRENT_IDENTITY_VALUE()"]
+                    result.records = identityValueResult
+                } catch (error) {
+                    throw new QueryFailedError(lastIdQuery, [], error)
+                }
            }
        } catch (err) {
            this.driver.connection.logger.logQueryError(
@ -311,7 +309,7 @@ export class SapQueryRunner extends BaseQueryRunner implements QueryRunner {
        } finally {
            // Never forget to drop the statement we reserved
            if (statement?.drop) {
-                await new Promise<void>((ok) => statement.drop(() => ok()))
+                await promisify(statement.drop).call(statement)
            }

            await broadcasterResult.wait()
@ -343,11 +341,15 @@ export class SapQueryRunner extends BaseQueryRunner implements QueryRunner {
        let resultSet: any

        const cleanup = async () => {
-            if (resultSet) {
-                await promisify(resultSet.close).call(resultSet)
+            const originalStatement = statement
+            const originalResultSet = resultSet
+            statement = null
+            resultSet = null
+            if (originalResultSet) {
+                await promisify(originalResultSet.close).call(originalResultSet)
            }
-            if (statement) {
-                await promisify(statement.drop).call(statement)
+            if (originalStatement) {
+                await promisify(originalStatement.drop).call(originalStatement)
            }
            release()
        }
@ -367,20 +369,20 @@ export class SapQueryRunner extends BaseQueryRunner implements QueryRunner {

            const stream =
                this.driver.streamClient.createObjectStream(resultSet)
-            stream.on("end", async () => {
-                await cleanup()
-                onEnd?.()
-            })
-            stream.on("error", async (error: Error) => {
+
+            if (onEnd) {
+                stream.on("end", onEnd)
+            }
+            stream.on("error", (error: Error) => {
                this.driver.connection.logger.logQueryError(
                    error,
                    query,
                    parameters,
                    this,
                )
-                await cleanup()
                onError?.(error)
            })
+            stream.on("close", cleanup)

            return stream
        } catch (error) {
--- a/src/platform/PlatformTools.ts
+++ b/src/platform/PlatformTools.ts
@ -60,9 +60,6 @@ export class PlatformTools {
                case "@sap/hana-client/extension/Stream":
                    return require("@sap/hana-client/extension/Stream")

-                case "hdb-pool":
-                    return require("hdb-pool")
-
                /**
                 * mysql
                 */
--- a/test/functional/driver/sap/connection-pool.ts
+++ b/test/functional/driver/sap/connection-pool.ts
@ -0,0 +1,72 @@
+import "reflect-metadata"
+import {
+    closeTestingConnections,
+    createTestingConnections,
+    reloadTestingDatabases,
+} from "../../../utils/test-utils"
+import { DataSource } from "../../../../src/data-source/DataSource"
+import { expect } from "chai"
+import { SapDriver } from "../../../../src/driver/sap/SapDriver"
+import { QueryRunner } from "../../../../src"
+import { ConnectionPool } from "@sap/hana-client"
+
+describe("driver > sap > connection pool", () => {
+    let dataSources: DataSource[]
+    before(
+        async () =>
+            (dataSources = await createTestingConnections({
+                enabledDrivers: ["sap"],
+                driverSpecific: {
+                    pool: {
+                        maxConnectedOrPooled: 3,
+                    },
+                },
+            })),
+    )
+    beforeEach(() => reloadTestingDatabases(dataSources))
+    after(() => closeTestingConnections(dataSources))
+
+    it("should be managed correctly", () =>
+        Promise.all(
+            dataSources.map(async (dataSource) => {
+                const poolClient = (dataSource.driver as SapDriver)
+                    .master as ConnectionPool
+                expect(poolClient.getInUseCount()).to.equal(0)
+                expect(poolClient.getPooledCount()).to.be.at.most(3)
+
+                const queryRunners: QueryRunner[] = []
+                for (let i = 0; i < 3; i++) {
+                    const queryRunner = dataSource.createQueryRunner()
+                    queryRunners.push(queryRunner)
+
+                    // the QueryRunner takes a connection from the pool once the first query is executed
+                    await queryRunner.sql`SELECT * FROM SYS.DUMMY`
+                }
+                expect(poolClient.getInUseCount()).to.equal(3)
+                expect(poolClient.getPooledCount()).to.equal(0)
+
+                const newQueryRunner = dataSource.createQueryRunner()
+                await expect(newQueryRunner.connect()).to.be.rejectedWith(
+                    "Unable to create connection, the maxConnectedOrPool limit has been reached",
+                )
+                await newQueryRunner.release()
+
+                const oldQueryRunner = queryRunners.pop()!
+                await oldQueryRunner.release()
+                expect(poolClient.getInUseCount()).to.equal(2)
+                expect(poolClient.getPooledCount()).to.equal(1)
+
+                const queryRunner = dataSource.createQueryRunner()
+                queryRunners.push(queryRunner)
+                await expect(queryRunner.connect()).to.be.fulfilled
+                expect(poolClient.getInUseCount()).to.equal(3)
+                expect(poolClient.getPooledCount()).to.equal(0)
+
+                for (const queryRunner of queryRunners) {
+                    await queryRunner.release()
+                }
+                expect(poolClient.getInUseCount()).to.equal(0)
+                expect(poolClient.getPooledCount()).to.equal(3)
+            }),
+        ))
+})