diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 1be94976bb..f12bb6f708 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -42,6 +42,11 @@ jobs:
       - name: Checking svelte sources...
         run: node common/scripts/install-run-rush.js svelte-check
 
+      - name: Start MongoDB
+        uses: supercharge/mongodb-github-action@1.3.0
+        with:
+          mongodb-version: 4.4
+
       - name: Testing...
         uses: paambaati/codeclimate-action@v2.7.5
         env:
diff --git a/server/mongo/package.json b/server/mongo/package.json
index 4c96533d64..0cc6e667e7 100644
--- a/server/mongo/package.json
+++ b/server/mongo/package.json
@@ -7,6 +7,7 @@
   "scripts": {
     "build": "heft build",
     "build:watch": "tsc",
+    "test": "heft test",
     "lint:fix": "eslint --fix src",
     "lint": "eslint src",
     "format": "prettier --write src && eslint --fix src"
diff --git a/server/mongo/src/__tests__/minmodel.ts b/server/mongo/src/__tests__/minmodel.ts
new file mode 100644
index 0000000000..02609f4649
--- /dev/null
+++ b/server/mongo/src/__tests__/minmodel.ts
@@ -0,0 +1,196 @@
+//
+// Copyright © 2020 Anticrm Platform Contributors.
+//
+// Licensed under the Eclipse Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License. You may
+// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import type { Account, Arr, Class, Data, Doc, Mixin, Obj, Ref, TxCreateDoc, TxCUD } from '@anticrm/core'
+import core, { AttachedDoc, ClassifierKind, DOMAIN_MODEL, DOMAIN_TX, TxFactory } from '@anticrm/core'
+import type { IntlString, Plugin } from '@anticrm/platform'
+import { plugin } from '@anticrm/platform'
+
+export const txFactory = new TxFactory(core.account.System)
+
+export function createClass (_class: Ref<Class<Obj>>, attributes: Data<Class<Obj>>): TxCreateDoc<Doc> {
+  return txFactory.createTxCreateDoc(core.class.Class, core.space.Model, attributes, _class)
+}
+
+/**
+ * @public
+ */
+export function createDoc<T extends Doc> (
+  _class: Ref<Class<T>>,
+  attributes: Data<T>,
+  id?: Ref<T>,
+  modifiedBy?: Ref<Account>
+): TxCreateDoc<Doc> {
+  const result = txFactory.createTxCreateDoc(_class, core.space.Model, attributes, id)
+  if (modifiedBy !== undefined) {
+    result.modifiedBy = modifiedBy
+  }
+  return result
+}
+
+/**
+ * @public
+ */
+export interface TestMixin extends Doc {
+  arr: Arr<string>
+}
+
+/**
+ * @public
+ */
+export interface AttachedComment extends AttachedDoc {
+  message: string
+}
+
+/**
+ * @public
+ */
+export const test = plugin('test' as Plugin, {
+  mixin: {
+    TestMixin: '' as Ref<Mixin<TestMixin>>
+  },
+  class: {
+    TestComment: '' as Ref<Class<AttachedComment>>
+  }
+})
+
+/**
+ * @public
+ * Generate minimal model for testing purposes.
+ * @returns R
+ */
+export function genMinModel (): TxCUD<Doc>[] {
+  const txes = []
+  // Fill Tx'es with basic model classes.
+  txes.push(createClass(core.class.Obj, { label: 'Obj' as IntlString, kind: ClassifierKind.CLASS }))
+  txes.push(
+    createClass(core.class.Doc, { label: 'Doc' as IntlString, extends: core.class.Obj, kind: ClassifierKind.CLASS })
+  )
+  txes.push(
+    createClass(core.class.AttachedDoc, {
+      label: 'AttachedDoc' as IntlString,
+      extends: core.class.Doc,
+      kind: ClassifierKind.MIXIN
+    })
+  )
+  txes.push(
+    createClass(core.class.Class, {
+      label: 'Class' as IntlString,
+      extends: core.class.Doc,
+      kind: ClassifierKind.CLASS,
+      domain: DOMAIN_MODEL
+    })
+  )
+  txes.push(
+    createClass(core.class.Space, {
+      label: 'Space' as IntlString,
+      extends: core.class.Doc,
+      kind: ClassifierKind.CLASS,
+      domain: DOMAIN_MODEL
+    })
+  )
+  txes.push(
+    createClass(core.class.Account, {
+      label: 'Account' as IntlString,
+      extends: core.class.Doc,
+      kind: ClassifierKind.CLASS,
+      domain: DOMAIN_MODEL
+    })
+  )
+
+  txes.push(
+    createClass(core.class.Tx, {
+      label: 'Tx' as IntlString,
+      extends: core.class.Doc,
+      kind: ClassifierKind.CLASS,
+      domain: DOMAIN_TX
+    })
+  )
+  txes.push(
+    createClass(core.class.TxCUD, {
+      label: 'TxCUD' as IntlString,
+      extends: core.class.Tx,
+      kind: ClassifierKind.CLASS,
+      domain: DOMAIN_TX
+    })
+  )
+  txes.push(
+    createClass(core.class.TxCreateDoc, {
+      label: 'TxCreateDoc' as IntlString,
+      extends: core.class.TxCUD,
+      kind: ClassifierKind.CLASS
+    })
+  )
+  txes.push(
+    createClass(core.class.TxUpdateDoc, {
+      label: 'TxUpdateDoc' as IntlString,
+      extends: core.class.TxCUD,
+      kind: ClassifierKind.CLASS
+    })
+  )
+  txes.push(
+    createClass(core.class.TxRemoveDoc, {
+      label: 'TxRemoveDoc' as IntlString,
+      extends: core.class.TxCUD,
+      kind: ClassifierKind.CLASS
+    })
+  )
+  txes.push(
+    createClass(core.class.TxCollectionCUD, {
+      label: 'TxCollectionCUD' as IntlString,
+      extends: core.class.TxCUD,
+      kind: ClassifierKind.CLASS
+    })
+  )
+
+  txes.push(
+    createClass(test.mixin.TestMixin, {
+      label: 'TestMixin' as IntlString,
+      extends: core.class.Doc,
+      kind: ClassifierKind.MIXIN
+    })
+  )
+
+  txes.push(
+    createClass(test.class.TestComment, {
+      label: 'TestComment' as IntlString,
+      extends: core.class.AttachedDoc,
+      kind: ClassifierKind.CLASS
+    })
+  )
+
+  const u1 = 'User1' as Ref<Account>
+  const u2 = 'User2' as Ref<Account>
+  txes.push(
+    createDoc(core.class.Account, { email: 'user1@site.com' }, u1),
+    createDoc(core.class.Account, { email: 'user2@site.com' }, u2),
+    createDoc(core.class.Space, {
+      name: 'Sp1',
+      description: '',
+      private: false,
+      members: [u1, u2]
+    })
+  )
+
+  txes.push(
+    createDoc(core.class.Space, {
+      name: 'Sp2',
+      description: '',
+      private: false,
+      members: [u1]
+    })
+  )
+  return txes
+}
diff --git a/server/mongo/src/__tests__/storage.test.ts b/server/mongo/src/__tests__/storage.test.ts
new file mode 100644
index 0000000000..eeb87125c1
--- /dev/null
+++ b/server/mongo/src/__tests__/storage.test.ts
@@ -0,0 +1,288 @@
+/* eslint-disable @typescript-eslint/no-non-null-assertion */
+//
+// Copyright © 2020 Anticrm Platform Contributors.
+//
+// Licensed under the Eclipse Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License. You may
+// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+import core, {
+  Class,
+  Client,
+  createClient,
+  Doc,
+  DocumentQuery,
+  DOMAIN_MODEL,
+  DOMAIN_TX,
+  FindOptions,
+  FindResult,
+  generateId,
+  Hierarchy, ModelDb,
+  Ref,
+  SortingOrder,
+  Space,
+  Tx,
+  TxOperations,
+  TxResult
+} from '@anticrm/core'
+import { createServerStorage, DbAdapter, DbConfiguration, FullTextAdapter, IndexedDoc } from '@anticrm/server-core'
+import { MongoClient } from 'mongodb'
+import { createMongoAdapter, createMongoTxAdapter } from '..'
+import { getMongoClient, shutdown } from '../utils'
+import { genMinModel } from './minmodel'
+import { createTaskModel, Task, TaskComment, taskPlugin } from './tasks'
+
+const txes = genMinModel()
+
+createTaskModel(txes)
+
+class NullDbAdapter implements DbAdapter {
+  async init (model: Tx[]): Promise<void> {}
+  async findAll<T extends Doc>(
+    _class: Ref<Class<T>>,
+    query: DocumentQuery<T>,
+    options?: FindOptions<T> | undefined
+  ): Promise<FindResult<T>> {
+    return []
+  }
+
+  async tx (tx: Tx): Promise<TxResult> {
+    return {}
+  }
+}
+
+async function createNullAdapter (hierarchy: Hierarchy, url: string, db: string, modelDb: ModelDb): Promise<DbAdapter> {
+  return new NullDbAdapter()
+}
+
+class NullFullTextAdapter implements FullTextAdapter {
+  async index (doc: IndexedDoc): Promise<TxResult> {
+    console.log('noop full text indexer: ', doc)
+    return {}
+  }
+
+  async update (id: Ref<Doc>, update: Record<string, any>): Promise<TxResult> {
+    return {}
+  }
+
+  async search (query: any): Promise<IndexedDoc[]> {
+    return []
+  }
+}
+
+async function createNullFullTextAdapter (): Promise<FullTextAdapter> {
+  return new NullFullTextAdapter()
+}
+
+describe('mongo operations', () => {
+  const mongodbUri: string = process.env.MONGODB_URI ?? 'mongodb://localhost:27017'
+  let mongoClient!: MongoClient
+  let dbId: string = generateId()
+  let hierarchy: Hierarchy
+  let model: ModelDb
+  let client: Client
+  let operations: TxOperations
+
+  beforeAll(async () => {
+    mongoClient = await getMongoClient(mongodbUri)
+  })
+
+  afterAll(async () => {
+    await shutdown()
+  })
+
+  beforeEach(async () => {
+    dbId = 'mongo-testdb-' + generateId()
+  })
+
+  afterEach(async () => {
+    try {
+      await mongoClient.db(dbId).dropDatabase()
+    } catch (eee) {}
+  })
+
+  async function initDb (): Promise<void> {
+    // Remove all stuff from database.
+    hierarchy = new Hierarchy()
+    model = new ModelDb(hierarchy)
+    for (const t of txes) {
+      await hierarchy.tx(t)
+    }
+    for (const t of txes) {
+      await model.tx(t)
+    }
+
+    const txStorage = await createMongoTxAdapter(hierarchy, mongodbUri, dbId, model)
+
+    // Put all transactions to Tx
+    for (const t of txes) {
+      await txStorage.tx(t)
+    }
+
+    const conf: DbConfiguration = {
+      domains: {
+        [DOMAIN_TX]: 'MongoTx',
+        [DOMAIN_MODEL]: 'Null'
+      },
+      defaultAdapter: 'Mongo',
+      adapters: {
+        MongoTx: {
+          factory: createMongoTxAdapter,
+          url: mongodbUri
+        },
+        Mongo: {
+          factory: createMongoAdapter,
+          url: mongodbUri
+        },
+        Null: {
+          factory: createNullAdapter,
+          url: ''
+        }
+      },
+      fulltextAdapter: {
+        factory: createNullFullTextAdapter,
+        url: ''
+      },
+      workspace: dbId
+    }
+    const serverStorage = await createServerStorage(conf)
+
+    client = await createClient(async (handler) => {
+      return await Promise.resolve(serverStorage)
+    })
+
+    operations = new TxOperations(client, core.account.System)
+  }
+
+  beforeEach(async () => {
+    return await initDb()
+  })
+
+  it('check add', async () => {
+    for (let i = 0; i < 50; i++) {
+      await operations.createDoc(taskPlugin.class.Task, '' as Ref<Space>, {
+        name: `my-task-${i}`,
+        description: `${i * i}`,
+        rate: 20 + i
+      })
+    }
+
+    const r = await client.findAll<Task>(taskPlugin.class.Task, {})
+    expect(r.length).toEqual(50)
+
+    const r2 = await client.findAll(core.class.Tx, {})
+    expect(r2.length).toBeGreaterThan(50)
+  })
+
+  it('check find by criteria', async () => {
+    for (let i = 0; i < 50; i++) {
+      await operations.createDoc(taskPlugin.class.Task, '' as Ref<Space>, {
+        name: `my-task-${i}`,
+        description: `${i * i}`,
+        rate: 20 + i
+      })
+    }
+
+    const r = await client.findAll<Task>(taskPlugin.class.Task, {})
+    expect(r.length).toEqual(50)
+
+    const first = await client.findAll<Task>(taskPlugin.class.Task, { name: 'my-task-0' })
+    expect(first.length).toEqual(1)
+
+    const second = await client.findAll<Task>(taskPlugin.class.Task, { name: { $like: '%0' } })
+    expect(second.length).toEqual(5)
+
+    const third = await client.findAll<Task>(taskPlugin.class.Task, { rate: { $in: [25, 26, 27, 28] } })
+    expect(third.length).toEqual(4)
+  })
+
+  it('check update', async () => {
+    await operations.createDoc(taskPlugin.class.Task, '' as Ref<Space>, {
+      name: 'my-task',
+      description: 'some data ',
+      rate: 20
+    })
+
+    const doc = (await client.findAll<Task>(taskPlugin.class.Task, {}))[0]
+
+    await operations.updateDoc(doc._class, doc.space, doc._id, { rate: 30 })
+    const tasks = await client.findAll<Task>(taskPlugin.class.Task, {})
+    expect(tasks.length).toEqual(1)
+    expect(tasks[0].rate).toEqual(30)
+  })
+
+  it('check remove', async () => {
+    for (let i = 0; i < 10; i++) {
+      await operations.createDoc(taskPlugin.class.Task, '' as Ref<Space>, {
+        name: `my-task-${i}`,
+        description: `${i * i}`,
+        rate: 20 + i
+      })
+    }
+
+    let r = await client.findAll<Task>(taskPlugin.class.Task, {})
+    expect(r.length).toEqual(10)
+    await operations.removeDoc<Task>(taskPlugin.class.Task, '' as Ref<Space>, r[0]._id)
+    r = await client.findAll<Task>(taskPlugin.class.Task, {})
+    expect(r.length).toEqual(9)
+  })
+
+  it('limit and sorting', async () => {
+    for (let i = 0; i < 5; i++) {
+      await operations.createDoc(taskPlugin.class.Task, '' as Ref<Space>, {
+        name: `my-task-${i}`,
+        description: `${i * i}`,
+        rate: 20 + i
+      })
+    }
+
+    const without = await client.findAll(taskPlugin.class.Task, {})
+    expect(without).toHaveLength(5)
+
+    const limit = await client.findAll(taskPlugin.class.Task, {}, { limit: 1 })
+    expect(limit).toHaveLength(1)
+
+    const sortAsc = await client.findAll(taskPlugin.class.Task, {}, { sort: { name: SortingOrder.Ascending } })
+    expect(sortAsc[0].name).toMatch('my-task-0')
+
+    const sortDesc = await client.findAll(taskPlugin.class.Task, {}, { sort: { name: SortingOrder.Descending } })
+    expect(sortDesc[0].name).toMatch('my-task-4')
+  })
+
+  it('check attached', async () => {
+    const docId = await operations.createDoc(taskPlugin.class.Task, '' as Ref<Space>, {
+      name: 'my-task',
+      description: 'Descr',
+      rate: 20
+    })
+
+    await operations.addCollection(taskPlugin.class.TaskComment, '' as Ref<Space>, docId, taskPlugin.class.Task, 'tasks', {
+      message: 'my-msg',
+      date: new Date()
+    })
+
+    await operations.addCollection(taskPlugin.class.TaskComment, '' as Ref<Space>, docId, taskPlugin.class.Task, 'tasks', {
+      message: 'my-msg2',
+      date: new Date()
+    })
+
+    const r = await client.findAll<Task>(taskPlugin.class.TaskComment, {})
+    expect(r.length).toEqual(2)
+
+    const r2 = await client.findAll<TaskComment>(taskPlugin.class.TaskComment, {}, {
+      lookup: {
+        attachedTo: taskPlugin.class.Task
+      }
+    })
+    expect(r2.length).toEqual(2)
+    console.log(JSON.stringify(r2, undefined, 2))
+    expect((r2[0].$lookup?.attachedTo as Task)?._id).toEqual(docId)
+  })
+})
diff --git a/server/mongo/src/__tests__/tasks.ts b/server/mongo/src/__tests__/tasks.ts
new file mode 100644
index 0000000000..3808430dd1
--- /dev/null
+++ b/server/mongo/src/__tests__/tasks.ts
@@ -0,0 +1,100 @@
+import { Account, AttachedDoc, Class, ClassifierKind, Data, Doc, Domain, Ref, Space, Tx } from '@anticrm/core'
+import { IntlString, plugin, Plugin } from '@anticrm/platform'
+import { createClass } from './minmodel'
+
+export interface TaskComment extends AttachedDoc {
+  message: string
+  date: Date
+}
+
+export enum TaskStatus {
+  Open,
+  Close,
+  Resolved = 100,
+  InProgress
+}
+
+export enum TaskReproduce {
+  Always = 'always',
+  Rare = 'rare',
+  Sometimes = 'sometimes'
+}
+
+export interface Task extends Doc {
+  name: string
+  description: string
+  rate?: number
+  status?: TaskStatus
+  reproduce?: TaskReproduce
+  eta?: TaskEstimate | null
+}
+
+/**
+ * Define ROM and Estimated Time to arrival
+ */
+export interface TaskEstimate extends AttachedDoc {
+  rom: number // in hours
+  eta: number // in hours
+}
+
+export interface TaskMixin extends Task {
+  textValue?: string
+}
+
+export interface TaskWithSecond extends Task {
+  secondTask: string | null
+}
+
+const taskIds = 'taskIds' as Plugin
+
+export const taskPlugin = plugin(taskIds, {
+  class: {
+    Task: '' as Ref<Class<Task>>,
+    TaskEstimate: '' as Ref<Class<TaskEstimate>>,
+    TaskComment: '' as Ref<Class<TaskComment>>
+  }
+})
+
+/**
+ * Create a random task with name specified
+ * @param name
+ */
+export function createTask (name: string, rate: number, description: string): Data<Task> {
+  return {
+    name,
+    description,
+    rate
+  }
+}
+
+export const doc1: Task = {
+  _id: 'd1' as Ref<Task>,
+  _class: taskPlugin.class.Task,
+  name: 'my-space',
+  description: 'some-value',
+  rate: 20,
+  modifiedBy: 'user' as Ref<Account>,
+  modifiedOn: 10,
+  // createOn: 10,
+  space: '' as Ref<Space>
+}
+
+export function createTaskModel (txes: Tx[]): void {
+  txes.push(
+    createClass(taskPlugin.class.Task, {
+      kind: ClassifierKind.CLASS,
+      label: 'Task' as IntlString,
+      domain: 'test-task' as Domain
+    }),
+    createClass(taskPlugin.class.TaskEstimate, {
+      kind: ClassifierKind.CLASS,
+      label: 'Estimate' as IntlString,
+      domain: 'test-task' as Domain
+    }),
+    createClass(taskPlugin.class.TaskComment, {
+      kind: ClassifierKind.CLASS,
+      label: 'Comment' as IntlString,
+      domain: 'test-task' as Domain
+    })
+  )
+}
diff --git a/server/mongo/src/storage.ts b/server/mongo/src/storage.ts
index 312def10f9..3598b5689e 100644
--- a/server/mongo/src/storage.ts
+++ b/server/mongo/src/storage.ts
@@ -13,29 +13,38 @@
 // limitations under the License.
 //
 
-import type { Tx, Ref, Doc, Class, DocumentQuery, FindResult, FindOptions, TxCreateDoc, TxUpdateDoc, TxMixin, TxPutBag, TxRemoveDoc, TxResult } from '@anticrm/core'
-import core, { DOMAIN_TX, DOMAIN_MODEL, SortingOrder, TxProcessor, Hierarchy, isOperator, ModelDb } from '@anticrm/core'
-
+import type {
+  Class,
+  Doc,
+  DocumentQuery,
+  FindOptions,
+  FindResult,
+  Ref,
+  Tx,
+  TxCreateDoc,
+  TxMixin,
+  TxPutBag,
+  TxRemoveDoc,
+  TxResult,
+  TxUpdateDoc
+} from '@anticrm/core'
+import core, { DOMAIN_MODEL, DOMAIN_TX, Hierarchy, isOperator, ModelDb, SortingOrder, TxProcessor } from '@anticrm/core'
 import type { DbAdapter, TxAdapter } from '@anticrm/server-core'
-
-import { MongoClient, Db, Filter, Document, Sort } from 'mongodb'
+import { Db, Document, Filter, Sort } from 'mongodb'
+import { getMongoClient } from './utils'
 
 function translateDoc (doc: Doc): Document {
   return doc as Document
 }
 
 abstract class MongoAdapterBase extends TxProcessor {
-  constructor (
-    protected readonly db: Db,
-    protected readonly hierarchy: Hierarchy,
-    protected readonly modelDb: ModelDb
-  ) {
+  constructor (protected readonly db: Db, protected readonly hierarchy: Hierarchy, protected readonly modelDb: ModelDb) {
     super()
   }
 
   async init (): Promise<void> {}
 
-  private translateQuery<T extends Doc> (clazz: Ref<Class<T>>, query: DocumentQuery<T>): Filter<Document> {
+  private translateQuery<T extends Doc>(clazz: Ref<Class<T>>, query: DocumentQuery<T>): Filter<Document> {
     const translated: any = {}
     for (const key in query) {
       const value = (query as any)[key]
@@ -62,7 +71,11 @@ abstract class MongoAdapterBase extends TxProcessor {
     return translated
   }
 
-  private async lookup<T extends Doc> (clazz: Ref<Class<T>>, query: DocumentQuery<T>, options: FindOptions<T>): Promise<FindResult<T>> {
+  private async lookup<T extends Doc>(
+    clazz: Ref<Class<T>>,
+    query: DocumentQuery<T>,
+    options: FindOptions<T>
+  ): Promise<FindResult<T>> {
     const pipeline = []
     pipeline.push({ $match: this.translateQuery(clazz, query) })
     const lookups = options.lookup as any
@@ -81,7 +94,7 @@ abstract class MongoAdapterBase extends TxProcessor {
     }
     const domain = this.hierarchy.getDomain(clazz)
     const cursor = this.db.collection(domain).aggregate(pipeline)
-    const result = await cursor.toArray() as FindResult<T>
+    const result = (await cursor.toArray()) as FindResult<T>
     for (const row of result) {
       const object = row as any
       object.$lookup = {}
@@ -99,17 +112,22 @@ abstract class MongoAdapterBase extends TxProcessor {
     return result
   }
 
-  async findAll<T extends Doc> (
+  async findAll<T extends Doc>(
     _class: Ref<Class<T>>,
     query: DocumentQuery<T>,
     options?: FindOptions<T>
   ): Promise<FindResult<T>> {
     // TODO: rework this
     if (options !== null && options !== undefined) {
-      if (options.lookup !== undefined) { return await this.lookup(_class, query, options) }
+      if (options.lookup !== undefined) {
+        return await this.lookup(_class, query, options)
+      }
     }
     const domain = this.hierarchy.getDomain(_class)
     let cursor = this.db.collection(domain).find<T>(this.translateQuery(_class, query))
+    if (options?.limit !== undefined) {
+      cursor = cursor.limit(options.limit)
+    }
     if (options !== null && options !== undefined) {
       if (options.sort !== undefined) {
         const sort: Sort = {}
@@ -127,7 +145,6 @@ abstract class MongoAdapterBase extends TxProcessor {
 class MongoAdapter extends MongoAdapterBase {
   protected override async txPutBag (tx: TxPutBag<any>): Promise<TxResult> {
     const domain = this.hierarchy.getDomain(tx.objectClass)
-    console.log('mongo', { $set: { [tx.bag + '.' + tx.key]: tx.value } })
     await this.db.collection(domain).updateOne({ _id: tx.objectId }, { $set: { [tx.bag + '.' + tx.key]: tx.value } })
     return {}
   }
@@ -186,40 +203,56 @@ class MongoAdapter extends MongoAdapterBase {
             }
           }
         ]
-        console.log('ops', ops)
         return await this.db.collection(domain).bulkWrite(ops as any)
       } else {
         if (tx.retrieve === true) {
-          const result = await this.db.collection(domain).findOneAndUpdate({ _id: tx.objectId }, {
-            ...tx.operations,
-            $set: {
-              modifiedBy: tx.modifiedBy,
-              modifiedOn: tx.modifiedOn
-            }
-          }, { returnDocument: 'after' })
+          const result = await this.db.collection(domain).findOneAndUpdate(
+            { _id: tx.objectId },
+            {
+              ...tx.operations,
+              $set: {
+                modifiedBy: tx.modifiedBy,
+                modifiedOn: tx.modifiedOn
+              }
+            },
+            { returnDocument: 'after' }
+          )
           return { object: result.value }
         } else {
-          return await this.db.collection(domain).updateOne({ _id: tx.objectId }, {
-            ...tx.operations,
-            $set: {
-              modifiedBy: tx.modifiedBy,
-              modifiedOn: tx.modifiedOn
+          return await this.db.collection(domain).updateOne(
+            { _id: tx.objectId },
+            {
+              ...tx.operations,
+              $set: {
+                modifiedBy: tx.modifiedBy,
+                modifiedOn: tx.modifiedOn
+              }
             }
-          })
+          )
         }
       }
     } else {
       if (tx.retrieve === true) {
-        const result = await this.db.collection(domain).findOneAndUpdate({ _id: tx.objectId }, { $set: { ...tx.operations, modifiedBy: tx.modifiedBy, modifiedOn: tx.modifiedOn } }, { returnDocument: 'after' })
+        const result = await this.db
+          .collection(domain)
+          .findOneAndUpdate(
+            { _id: tx.objectId },
+            { $set: { ...tx.operations, modifiedBy: tx.modifiedBy, modifiedOn: tx.modifiedOn } },
+            { returnDocument: 'after' }
+          )
         return { object: result.value }
       } else {
-        return await this.db.collection(domain).updateOne({ _id: tx.objectId }, { $set: { ...tx.operations, modifiedBy: tx.modifiedBy, modifiedOn: tx.modifiedOn } })
+        return await this.db
+          .collection(domain)
+          .updateOne(
+            { _id: tx.objectId },
+            { $set: { ...tx.operations, modifiedBy: tx.modifiedBy, modifiedOn: tx.modifiedOn } }
+          )
       }
     }
   }
 
   override tx (tx: Tx): Promise<TxResult> {
-    console.log('mongo', tx)
     return super.tx(tx)
   }
 }
@@ -246,7 +279,6 @@ class MongoTxAdapter extends MongoAdapterBase implements TxAdapter {
   }
 
   override async tx (tx: Tx): Promise<TxResult> {
-    console.log('mongotx', tx)
     await this.db.collection(DOMAIN_TX).insertOne(translateDoc(tx))
     return {}
   }
@@ -259,9 +291,13 @@ class MongoTxAdapter extends MongoAdapterBase implements TxAdapter {
 /**
  * @public
  */
-export async function createMongoAdapter (hierarchy: Hierarchy, url: string, dbName: string, modelDb: ModelDb): Promise<DbAdapter> {
-  const client = new MongoClient(url)
-  await client.connect()
+export async function createMongoAdapter (
+  hierarchy: Hierarchy,
+  url: string,
+  dbName: string,
+  modelDb: ModelDb
+): Promise<DbAdapter> {
+  const client = await getMongoClient(url)
   const db = client.db(dbName)
   return new MongoAdapter(db, hierarchy, modelDb)
 }
@@ -269,9 +305,13 @@ export async function createMongoAdapter (hierarchy: Hierarchy, url: string, dbN
 /**
  * @public
  */
-export async function createMongoTxAdapter (hierarchy: Hierarchy, url: string, dbName: string, modelDb: ModelDb): Promise<TxAdapter> {
-  const client = new MongoClient(url)
-  await client.connect()
+export async function createMongoTxAdapter (
+  hierarchy: Hierarchy,
+  url: string,
+  dbName: string,
+  modelDb: ModelDb
+): Promise<TxAdapter> {
+  const client = await getMongoClient(url)
   const db = client.db(dbName)
   return new MongoTxAdapter(db, hierarchy, modelDb)
 }
diff --git a/server/mongo/src/utils.ts b/server/mongo/src/utils.ts
new file mode 100644
index 0000000000..067f575f33
--- /dev/null
+++ b/server/mongo/src/utils.ts
@@ -0,0 +1,46 @@
+//
+// Copyright © 2021 Anticrm Platform Contributors.
+//
+// Licensed under the Eclipse Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License. You may
+// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import { MongoClient, MongoClientOptions } from 'mongodb'
+
+const connections = new Map<string, Promise<MongoClient>>()
+
+// Register mongo close on process exit.
+process.on('exit', () => {
+  shutdown().catch((err) => console.error(err))
+})
+
+/**
+ * @public
+ */
+export async function shutdown (): Promise<void> {
+  for (const c of connections.values()) {
+    await (await c).close()
+  }
+  connections.clear()
+}
+/**
+ * Initialize a workspace connection to DB
+ * @public
+ */
+export async function getMongoClient (uri: string, options?: MongoClientOptions): Promise<MongoClient> {
+  let client = connections.get(uri)
+  if (client === undefined) {
+    client = MongoClient.connect(uri, { ...options })
+    await client
+    connections.set(uri, client)
+  }
+  return await client
+}