Merge pull request neo4j#490 from ali-ince/4.0-purge-aged-routing-tables

Purge old routing table entries on inactivity

Author: zhenlineo

src/internal/connection-provider-routing.js

@@ -31,12 +31,14 @@ import ConnectionErrorHandler from './connection-error-handler'
 import DelegateConnection from './connection-delegate'
 import LeastConnectedLoadBalancingStrategy from './least-connected-load-balancing-strategy'
 import Bookmark from './bookmark'
+import { int } from '../integer'
 
 const UNAUTHORIZED_ERROR_CODE = 'Neo.ClientError.Security.Unauthorized'
 const DATABASE_NOT_FOUND_ERROR_CODE =
  'Neo.ClientError.Database.DatabaseNotFound'
 const SYSTEM_DB_NAME = 'system'
 const DEFAULT_DB_NAME = ''
+const DEFAULT_ROUTING_TABLE_PURGE_DELAY = int(30000)
 
 export default class RoutingConnectionProvider extends PooledConnectionProvider {
  constructor ({
@@ -47,7 +49,8 @@ export default class RoutingConnectionProvider extends PooledConnectionProvider
  config,
  log,
  userAgent,
- authToken
+ authToken,
+ routingTablePurgeDelay
  }) {
  super({ id, config, log, userAgent, authToken })
 
@@ -61,6 +64,9 @@ export default class RoutingConnectionProvider extends PooledConnectionProvider
  this._dnsResolver = new HostNameResolver()
  this._log = log
  this._useSeedRouter = true
+ this._routingTablePurgeDelay = routingTablePurgeDelay
+ ? int(routingTablePurgeDelay)
+ : DEFAULT_ROUTING_TABLE_PURGE_DELAY
  }
 
  _createConnectionErrorHandler () {
@@ -71,23 +77,15 @@ export default class RoutingConnectionProvider extends PooledConnectionProvider
 
  _handleUnavailability (error, address, database) {
  this._log.warn(
- `Routing driver ${
- this._id
- } will forget ${address} for database '${database}' because of an error ${
- error.code
- } '${error.message}'`
+ `Routing driver ${this._id} will forget ${address} for database '${database}' because of an error ${error.code} '${error.message}'`
  )
  this.forget(address, database || '')
  return error
  }
 
  _handleWriteFailure (error, address, database) {
  this._log.warn(
- `Routing driver ${
- this._id
- } will forget writer ${address} for database '${database}' because of an error ${
- error.code
- } '${error.message}'`
+ `Routing driver ${this._id} will forget writer ${address} for database '${database}' because of an error ${error.code} '${error.message}'`
  )
  this.forgetWriter(address, database || '')
  return newError(
@@ -427,6 +425,13 @@ export default class RoutingConnectionProvider extends PooledConnectionProvider
  // close old connections to servers not present in the new routing table
  await this._connectionPool.keepAll(newRoutingTable.allServers())
 
+ // filter out expired to purge (expired for a pre-configured amount of time) routing table entries
+ Object.values(this._routingTables).forEach(value => {
+ if (value.isExpiredFor(this._routingTablePurgeDelay)) {
+ delete this._routingTables[value.database]
+ }
+ })
+
  // make this driver instance aware of the new table
  this._routingTables[newRoutingTable.database] = newRoutingTable
  this._log.info(`Updated routing table ${newRoutingTable}`)

src/internal/routing-table.js

@@ -24,6 +24,7 @@ const MIN_ROUTERS = 1
 export default class RoutingTable {
  constructor ({ database, routers, readers, writers, expirationTime } = {}) {
  this.database = database
+ this.databaseName = database || 'default database'
  this.routers = routers || []
  this.readers = readers || []
  this.writers = writers || []
@@ -61,14 +62,24 @@ export default class RoutingTable {
  )
  }
 
+ /**
+ * Check if this routing table is expired for specified amount of duration
+ *
+ * @param {Integer} duration amount of duration in milliseconds to check for expiration
+ * @returns {boolean}
+ */
+ isExpiredFor (duration) {
+ return this.expirationTime.add(duration).lessThan(Date.now())
+ }
+
  allServers () {
  return [...this.routers, ...this.readers, ...this.writers]
  }
 
  toString () {
  return (
- `RoutingTable[` +
- `database=${this.database}, ` +
+ 'RoutingTable[' +
+ `database=${this.databaseName}, ` +
  `expirationTime=${this.expirationTime}, ` +
  `currentTime=${Date.now()}, ` +
  `routers=[${this.routers}], ` +

test/internal/connection-provider-routing.test.js

@@ -1723,6 +1723,92 @@ describe('#unit RoutingConnectionProvider', () => {
  [serverC]
  )
  })
+
+ it('should purge expired routing tables after specified duration on update', async () => {
+ var originalDateNow = Date.now
+ Date.now = () => 50000
+ try {
+ const routingTableToLoad = newRoutingTable(
+ 'databaseC',
+ [server1, server2, server3],
+ [server2, server3],
+ [server1]
+ )
+ const connectionProvider = newRoutingConnectionProviderWithSeedRouter(
+ server1,
+ [server1],
+ [
+ newRoutingTable(
+ 'databaseA',
+ [server1, server2, server3],
+ [server1, server2],
+ [server3],
+ int(Date.now() + 12000)
+ ),
+ newRoutingTable(
+ 'databaseB',
+ [server1, server2, server3],
+ [server1, server3],
+ [server2],
+ int(Date.now() + 2000)
+ )
+ ],
+ {
+ databaseC: {
+ 'server1:7687': routingTableToLoad
+ }
+ },
+ null,
+ 4000
+ )
+
+ expectRoutingTable(
+ connectionProvider,
+ 'databaseA',
+ [server1, server2, server3],
+ [server1, server2],
+ [server3]
+ )
+ expectRoutingTable(
+ connectionProvider,
+ 'databaseB',
+ [server1, server2, server3],
+ [server1, server3],
+ [server2]
+ )
+
+ // make routing table for databaseA to report true for isExpiredFor(4000)
+ // call.
+ Date.now = () => 58000
+
+ // force a routing table update for databaseC
+ const conn1 = await connectionProvider.acquireConnection({
+ accessMode: WRITE,
+ database: 'databaseC'
+ })
+ expect(conn1).not.toBeNull()
+ expect(conn1.address).toBe(server1)
+
+ // Then
+ expectRoutingTable(
+ connectionProvider,
+ 'databaseA',
+ [server1, server2, server3],
+ [server1, server2],
+ [server3]
+ )
+ expectRoutingTable(
+ connectionProvider,
+ 'databaseC',
+ [server1, server2, server3],
+ [server2, server3],
+ [server1]
+ )
+ expectNoRoutingTable(connectionProvider, 'databaseB')
+ } finally {
+ Date.now = originalDateNow
+ }
+ })
  })
 })
 
@@ -1746,7 +1832,8 @@ function newRoutingConnectionProviderWithSeedRouter (
  seedRouterResolved,
  routingTables,
  routerToRoutingTable = { '': {} },
- connectionPool = null
+ connectionPool = null,
+ routingTablePurgeDelay = null
 ) {
  const pool = connectionPool || newPool()
  const connectionProvider = new RoutingConnectionProvider({
@@ -1755,7 +1842,8 @@ function newRoutingConnectionProviderWithSeedRouter (
  routingContext: {},
  hostNameResolver: new SimpleHostNameResolver(),
  config: {},
- log: Logger.noOp()
+ log: Logger.noOp(),
+ routingTablePurgeDelay: routingTablePurgeDelay
  })
  connectionProvider._connectionPool = pool
  routingTables.forEach(r => {
@@ -1821,6 +1909,10 @@ function expectRoutingTable (
  expect(connectionProvider._routingTables[database].writers).toEqual(writers)
 }
 
+function expectNoRoutingTable (connectionProvider, database) {
+ expect(connectionProvider._routingTables[database]).toBeFalsy()
+}
+
 function expectPoolToContain (pool, addresses) {
  addresses.forEach(address => {
  expect(pool.has(address)).toBeTruthy()

test/internal/routing-table.test.js

@@ -201,8 +201,29 @@ describe('#unit RoutingTable', () => {
  }
  })
 
- function expired () {
- return Date.now() - 3600 // expired an hour ago
+ it('should report correct value when expired for is tested', () => {
+ const originalDateNow = Date.now
+ try {
+ Date.now = () => 50000
+ const table = createTable(
+ [server1, server2, server3],
+ [server2, server1, server5],
+ [server5, server1],
+ expired(7200)
+ )
+
+ expect(table.isStaleFor(READ)).toBeTruthy()
+ expect(table.isStaleFor(WRITE)).toBeTruthy()
+
+ expect(table.isExpiredFor(3600)).toBeTruthy()
+ expect(table.isExpiredFor(10800)).toBeFalsy()
+ } finally {
+ Date.now = originalDateNow
+ }
+ })
+
+ function expired (expiredFor) {
+ return Date.now() - (expiredFor || 3600) // expired an hour ago
  }
 
  function notExpired () {

test/rx/summary.test.js

@@ -578,7 +578,7 @@ describe('#integration-rx summary', () => {
  'The provided label is not in the database.'
  )
  expect(summary.notifications[0].description).toBe(
- 'One of the labels in your query is not available in the database, make sure you didn\'t misspell it or that the label is available when you run this statement in your application (the missing label name is: ThisLabelDoesNotExist)'
+ "One of the labels in your query is not available in the database, make sure you didn't misspell it or that the label is available when you run this statement in your application (the missing label name is: ThisLabelDoesNotExist)"
  )
  expect(summary.notifications[0].severity).toBe('WARNING')
  }
@@ -652,20 +652,25 @@ describe('#integration-rx summary', () => {
  }
 
  async function dropConstraintsAndIndices (driver) {
+ function getName (record) {
+ const obj = record.toObject()
+ const name = obj.description || obj.name
+ if (!name) {
+ throw new Error('unable to identify name of the constraint/index')
+ }
+ return name
+ }
+
  const session = driver.session()
  try {
- const constraints = await session.run(
- "CALL db.constraints() yield description RETURN 'DROP ' + description"
- )
+ const constraints = await session.run('CALL db.constraints()')
  for (let i = 0; i < constraints.records.length; i++) {
- await session.run(constraints.records[0].get(0))
+ await session.run(`DROP ${getName(constraints.records[i])}`)
  }
 
- const indices = await session.run(
- "CALL db.indexes() yield description RETURN 'DROP ' + description"
- )
+ const indices = await session.run('CALL db.indexes()')
  for (let i = 0; i < indices.records.length; i++) {
- await session.run(indices.records[0].get(0))
+ await session.run(`DROP ${getName(indices.records[i])}`)
  }
  } finally {
  await session.close()

test/session.test.js

@@ -171,7 +171,7 @@ describe('#integration session', () => {
  it('should accept a statement object ', done => {
  // Given
  const statement = {
- text: 'RETURN 1 = {param} AS a',
+ text: 'RETURN 1 = $param AS a',
  parameters: { param: 1 }
  }
 
@@ -215,7 +215,7 @@ describe('#integration session', () => {
 
  it('should expose summarize method for basic metadata ', done => {
  // Given
- const statement = 'CREATE (n:Label {prop:{prop}}) RETURN n'
+ const statement = 'CREATE (n:Label {prop: $prop}) RETURN n'
  const params = { prop: 'string' }
  // When & Then
  session.run(statement, params).then(result => {
@@ -269,7 +269,7 @@ describe('#integration session', () => {
 
  it('should expose plan ', done => {
  // Given
- const statement = 'EXPLAIN CREATE (n:Label {prop:{prop}}) RETURN n'
+ const statement = 'EXPLAIN CREATE (n:Label {prop: $prop}) RETURN n'
  const params = { prop: 'string' }
  // When & Then
  session.run(statement, params).then(result => {
@@ -286,7 +286,7 @@ describe('#integration session', () => {
 
  it('should expose profile ', done => {
  // Given
- const statement = 'PROFILE MATCH (n:Label {prop:{prop}}) RETURN n'
+ const statement = 'PROFILE MATCH (n:Label {prop: $prop}) RETURN n'
  const params = { prop: 'string' }
  // When & Then
  session.run(statement, params).then(result => {
@@ -403,7 +403,7 @@ describe('#integration session', () => {
  throw Error()
  }
 
- const statement = 'RETURN {param}'
+ const statement = 'RETURN $param'
  const params = { param: unpackable }
  // When & Then
  session.run(statement, params).catch(ignore => {
@@ -883,20 +883,20 @@ describe('#integration session', () => {
  it('should be able to do nested queries', done => {
  session
  .run(
- 'CREATE (knight:Person:Knight {name: {name1}, castle: {castle}})' +
- 'CREATE (king:Person {name: {name2}, title: {title}})',
+ 'CREATE (knight:Person:Knight {name: $name1, castle: $castle})' +
+ 'CREATE (king:Person {name: $name2, title: $title})',
  { name1: 'Lancelot', castle: 'Camelot', name2: 'Arthur', title: 'King' }
  )
  .then(() => {
  session
  .run(
- 'MATCH (knight:Person:Knight) WHERE knight.castle = {castle} RETURN id(knight) AS knight_id',
+ 'MATCH (knight:Person:Knight) WHERE knight.castle = $castle RETURN id(knight) AS knight_id',
  { castle: 'Camelot' }
  )
  .subscribe({
  onNext: record => {
  session.run(
- 'MATCH (knight) WHERE id(knight) = {id} MATCH (king:Person) WHERE king.name = {king} CREATE (knight)-[:DEFENDS]->(king)',
+ 'MATCH (knight) WHERE id(knight) = $id MATCH (king:Person) WHERE king.name = $king CREATE (knight)-[:DEFENDS]->(king)',
  { id: record.get('knight_id'), king: 'Arthur' }
  )
  },