Introduction to 3.0

By: Osmar “Oz” Olivo

Product Manager

MongoDB Inc.

Agenda

• Pluggable Storage Engines• WiredTiger Integration• Concurrency• Compression• Enhanced Querying & Tools• Administration Enhancements• Replication Enhancements

Pluggable Storage Engines

• Vision– One data model, one API, one set of operational

concerns » Under the hood, many options for every use

case under the sun

Storage Engine Layer

Storage Engine Layer

Content Repo

IoT Sensor Backend

Ad ServiceCustomer Analytics

Archive

MongoDB Query Language (MQL) + Native Drivers

MongoDB Document Data Model

MMAP V1 WT In-Memory ? ?

Supported in MongoDB 3.0 Future Possible Storage Engines

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Experimental in MongoDB 3.0

WiredTiger Integration

Why WT?

They’re Grrrreat!

Why WT?

• WT product and team acquired by MongoDB– Authors former members of Berkeley DB team– Standalone engine in use in production today

• WT addresses weaknesses of MMAPv1– Compression– Highly concurrent and enables full hardware utilization– More tunable

Concurrency

MMAPv1 Concurrency Improvements

• Collection Level Concurrency– One lock per collection– Write operations to a collection block all other

operations on that collection– Read operations to a collection block writes to that

collection• Allow other read operations to occur concurrently

Concurrency in WiredTiger

• Document Level Concurrency – Uses various algorithms to minimize contention

between threads– One thread yields on contention to same document

• Writes no longer block all other writes • CPU utilization directly correlates with performance

Compression

Compression (WT only)

• Compression is on in WT by default• 3.0 supports two compression algorithms

– snappy (default)• Good compression benefits with little

CPU/performance impact– zlib

• Extremely good compression at a cost of additional CPU/degraded performance

Enhanced Querying & Tools

Indexing & Querying

• Explain() 2.0– explain() revamped

• Now allows for improved query inspection• Geospatial Big Polygon support

– Improved handling of polygons with an area greater than a single hemisphere

• $dateToString operator in aggregation – Allows user to specify string format for which to

convert a date into

Tools Improvements

• MongoDB Server Tools Rewritten in GO– Removed all server dependencies– Allows for much faster iteration

• Parallelized data loading tools– dump/restore & import/export– highly improved loading and export times

Administration Enhancements

Administration

• Role Based Auditing– Auditing rules can be set to filter on specific roles– Useful for auditing certain kinds of accesses or users

• Logging Improvements– New component system– Able to filter by severity levels

Replication

Replication

• Replica set limit raised from 12 to 50• Meets a much higher HA standard

– Can deploy across many more regions and DC’s– Increases locality of data across deployments– Easier to guarantee local reads across many regions

Questions?