fix(assetlibrary): change connection life cycle between Lambda and Ne…

…ptune

source/common/changes/@awssolutions/cdf-assetlibrary/main_2023-10-06-06-40.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@awssolutions/cdf-assetlibrary",
+      "comment": "Change connection life cycle between Lambda and Neptune",
+      "type": "none"
+    }
+  ],
+  "packageName": "@awssolutions/cdf-assetlibrary"
+}

source/packages/services/assetlibrary/src/@types/gremlin/index.d.ts

@@ -414,7 +414,10 @@ declare module 'gremlin' {
         export class RemoteStrategy extends process.TraversalStrategy {}
 
         export class DriverRemoteConnection extends RemoteConnection {
+            open(): Promise<void>;
             close(): Promise<void>;
+            addListener(event: string | symbol, handler: (...args: any[]) => void): void;
+            removeListener(event: string | symbol, handler: (...args: any[]) => void): void;
         }
     }
 }

source/packages/services/assetlibrary/src/authz/authz.full.dao.ts

@@ -48,44 +48,39 @@ export class AuthzDaoFull extends BaseDaoFull {
         const ids: string[] = deviceIds.map((d) => `device___${d}`);
         ids.push(...groupPaths.map((g) => `group___${g}`));
 
-        let results;
-        const conn = super.getConnection();
-        try {
-            const traverser = conn.traversal
-                .V(ids)
-                .as('entity')
-                .union(
-                    // return an item if the entity exists
-                    __.project('entity', 'exists')
-                        .by(
-                            __.select('entity').coalesce(
-                                __.values('deviceId'),
-                                __.values('groupPath')
-                            )
+        const conn = await super.getConnection();
+        const traverser = conn.traversal
+            .V(ids)
+            .as('entity')
+            .union(
+                // return an item if the entity exists
+                __.project('entity', 'exists')
+                    .by(
+                        __.select('entity').coalesce(
+                            __.values('deviceId'),
+                            __.values('groupPath')
                         )
-                        .by(__.constant(true)),
-                    // return an item if the entity is authorized
-                    __.local(
-                        __.until(__.has('groupPath', process.P.within(hierarchies)))
-                            .repeat(
-                                __.outE().has('isAuthCheck', true).otherV().simplePath().dedup()
-                            )
-                            .as('authorizedPath')
                     )
-                        .project('entity', 'authorizedPath')
-                        .by(
-                            __.select('entity').coalesce(
-                                __.values('deviceId'),
-                                __.values('groupPath')
-                            )
+                    .by(__.constant(true)),
+                // return an item if the entity is authorized
+                __.local(
+                    __.until(__.has('groupPath', process.P.within(hierarchies)))
+                        .repeat(
+                            __.outE().has('isAuthCheck', true).otherV().simplePath().dedup()
                         )
-                        .by(__.select('authorizedPath').values('groupPath'))
-                );
+                        .as('authorizedPath')
+                )
+                    .project('entity', 'authorizedPath')
+                    .by(
+                        __.select('entity').coalesce(
+                            __.values('deviceId'),
+                            __.values('groupPath')
+                        )
+                    )
+                    .by(__.select('authorizedPath').values('groupPath'))
+            );
 
-            results = await traverser.toList();
-        } finally {
-            await conn.close();
-        }
+        const results = await traverser.toList();
 
         logger.debug(
             `authz.full.dao listAuthorizedHierarchies: results:${JSON.stringify(results)}`

source/packages/services/assetlibrary/src/data/base.full.dao.ts

@@ -18,23 +18,40 @@ import { TYPES } from '../di/types';
 @injectable()
 export class BaseDaoFull {
     private _graph: structure.Graph;
+    private _conn: driver.DriverRemoteConnection | null;
 
     public constructor(
         @inject('neptuneUrl') private neptuneUrl: string,
         @inject(TYPES.GraphSourceFactory) graphSourceFactory: () => structure.Graph
     ) {
         this._graph = graphSourceFactory();
+        this._conn = null;
     }
 
-    protected getConnection(): NeptuneConnection {
+    protected async getConnection(): Promise<NeptuneConnection> {
         logger.debug(`base.full.dao getConnection: in:`);
-        const conn = new driver.DriverRemoteConnection(this.neptuneUrl, {
-            mimeType: 'application/vnd.gremlin-v2.0+json',
-            pingEnabled: false,
-        });
+
+        if (this._conn == null) {
+            logger.debug(`base.full.dao getConnection: create new connection:`);
+            this._conn = new driver.DriverRemoteConnection(this.neptuneUrl, {
+                mimeType: 'application/vnd.gremlin-v2.0+json',
+                pingEnabled: false,
+                connectOnStartup: false,
+            });
+            this._conn.addListener('close', (code: number, message: string) => {
+                logger.info(`base.full.dao connection close: code: ${code}, message: ${message}`);
+                this._conn = null;
+                if (code === 1006) {
+                    throw new Error('Connection closed prematurely');
+                }
+            });
+            await this._conn.open();
+        }
 
         logger.debug(`base.full.dao getConnection: withRemote:`);
-        const res = new NeptuneConnection(this._graph.traversal().withRemote(conn), conn);
+        const res = new NeptuneConnection(
+            this._graph.traversal().withRemote(this._conn),
+        );
 
         logger.debug(`base.full.dao getConnection: exit:`);
         return res;
@@ -44,14 +61,9 @@ export class BaseDaoFull {
 export class NeptuneConnection {
     constructor(
         private _traversal: process.GraphTraversalSource,
-        private _connection: driver.DriverRemoteConnection
     ) {}
 
     public get traversal(): process.GraphTraversalSource {
         return this._traversal;
     }
-
-    public async close(): Promise<void> {
-        await this._connection.close();
-    }
 }

source/packages/services/assetlibrary/src/data/common.full.dao.ts

@@ -146,26 +146,21 @@ export class CommonDaoFull extends BaseDaoFull {
         relatedUnion.range(offsetAsInt, offsetAsInt + countAsInt);
 
         // build the main part of the query, unioning the related traversers with the main entity we want to return
-        let results;
-        const conn = super.getConnection();
-        try {
-            const traverser = conn.traversal
-                .V(entityDbId)
-                .as('main')
-                .union(
-                    relatedUnion,
-                    __.select('main').valueMap().with_(process.withOptions.tokens)
-                );
-
-            // execute and retrieve the results
-            logger.debug(
-                `common.full.dao listRelated: traverser: ${JSON.stringify(traverser.toString())}`
+        const conn = await super.getConnection();
+        const traverser = conn.traversal
+            .V(entityDbId)
+            .as('main')
+            .union(
+                relatedUnion,
+                __.select('main').valueMap().with_(process.withOptions.tokens)
             );
-            results = await traverser.toList();
-            logger.debug(`common.full.dao listRelated: results: ${JSON.stringify(results)}`);
-        } finally {
-            await conn.close();
-        }
+
+        // execute and retrieve the results
+        logger.debug(
+            `common.full.dao listRelated: traverser: ${JSON.stringify(traverser.toString())}`
+        );
+        const results = await traverser.toList();
+        logger.debug(`common.full.dao listRelated: results: ${JSON.stringify(results)}`);
 
         if (results === undefined || results.length === 0) {
             logger.debug(`common.full.dao listRelated: exit: node: undefined`);
@@ -193,20 +188,15 @@ export class CommonDaoFull extends BaseDaoFull {
             return {};
         }
 
-        let results;
-        const conn = super.getConnection();
-        try {
-            const query = conn.traversal
-                .V(entityDbIds)
-                .project('id', 'labels')
-                .by(__.coalesce(__.values('deviceId'), __.values('groupPath')))
-                .by(__.label().fold());
-
-            logger.silly(`common.full.dao getLabels: query: ${JSON.stringify(query)}`);
-            results = await query.toList();
-        } finally {
-            await conn.close();
-        }
+        const conn = await super.getConnection();
+        const query = conn.traversal
+            .V(entityDbIds)
+            .project('id', 'labels')
+            .by(__.coalesce(__.values('deviceId'), __.values('groupPath')))
+            .by(__.label().fold());
+
+        logger.silly(`common.full.dao getLabels: query: ${JSON.stringify(query)}`);
+        const results = await query.toList();
         logger.silly(`common.full.dao getLabels: results: ${JSON.stringify(results)}`);
 
         if ((results?.length ?? 0) === 0) {