Skip to content

Latest commit

 

History

History
146 lines (119 loc) · 4.58 KB

README.md

File metadata and controls

146 lines (119 loc) · 4.58 KB
Raw

Overview

Comdb2 is a clustered RDBMS built on Optimistic Concurrency Control techniques. It provides multiple isolation levels, including Snapshot and Serializable Isolation. Read/Write transactions run on any node, with client library transparently negotiating connections to lowest cost (latency) node which is available. Client library provides transparent reconnect.

Work on Comdb2 was started at Bloomberg LP in 2004 and it has been under heavy development since. More information about the architechture of the project can be found in our VLDB 2016 paper and for more information on usage please look in in the Docs.

Build

Comdb2 Directory Contents

Directory Description
bb/ Useful generic modules
bbinc/ Header files
bdb/ Table layer
bbinc/ Generic include files
berkdb/ Btrees layer
cdb2api/ Client code
cdb2jdbc/ JDBC driver
comdb2rle/ Run length encoding
comdb2tests/ Contains all the tests that will be run for this version
config/ lrl config files
contrib/ Misc useful programs that aren't part of core Comdb2
crc32c/ Checksum component
csc2/ csc2 processing
csc2files/ csc2 config files
cson/ JSON library
datetime/ Datetime component
db/ Types layer and overall glue
deb/ Sample debian package config
dfp/ Decimal number component
dlmalloc/ Local malloc version
docs/ Documentation
lua/ All things pertaining to lua VM used for stored procedures
net/ Network component
protobuf/ API to communicate with the server
schemachange Code for table create/alter/truncate/etc
sqlite/ Sqlite VM SQL engine
tests/ Comdb2 test suite
tools/ Tools that are part of Comdb2 core

Documentation

Comdb2 documentation is included in the docs directory. It can be hosted locally with jekyll by running jekyll serve from the docs directory.

Quick Start

On every machine in the cluster:

  1. Make sure all machines in the cluster can talk to each other via ssh. Copy keys around if needed.

  2. Install prerequisites:

    ** Ubuntu 16.04, 16.10 **

    sudo apt-get install -y build-essential bison flex libprotobuf-c-dev   \
libreadline-dev libsqlite3-dev libssl-dev libunwind-dev libz1 libz-dev \
make gawk protobuf-c-compiler uuid-dev liblz4-tool liblz4-dev          \
libprotobuf-c1 libreadline6 libsqlite3-0 libuuid1 libz1 tzdata         \
ncurses-dev tcl bc

    ** CentOS 7 **

    sudo yum install -y gcc gcc-c++ protobuf-c libunwind libunwind-devel   \
protobuf-c-devel byacc flex openssl openssl-devel openssl-libs         \
readline-devel sqlite sqlite-devel libuuid libuuid-devel zlib-devel    \
zlib lz4-devel gawk tcl epel-release lz4

  3. Build Comdb2:

    make && sudo make install

  4. Add /opt/bb/bin to your PATH

    export PATH=$PATH:/opt/bb/bin

  5. Start pmux:

    pmux -n

  6. We need to tell comdb2 our FQDN - all nodes must agree on each other's names:

    vi /opt/bb/etc/cdb2/config/comdb2.d/hostname.lrl
configure add current machine's name, e.g.
hostname mptest-1.comdb2.example.com

  7. On one machine, create a database.

    comdb2 --create --dir /home/mponomar/db mikedb

  8. Configure the nodes in the cluster:

    vi /home/mponomar/db/mikedb.lrl
add
cluster nodes mptest-1.comdb2.example.com mptest-2.comdb2.example.com

  9. On other nodes, copy the database over:

    copycomdb2 mptest-1.comdb2.example.com:/home/mponomar/db/mikedb.lrl

  10. On all nodes, start the database.

    comdb2 --lrl /home/mponomar/db/mikedb.lrl mikedb

    All nodes will say 'I AM READY.' when ready.

  11. On any node, start using the database. You don't have any tables yet. You can add them with cdb2sql Example -

    cdb2sql mikedb local 'CREATE TABLE t1 {
     schema {
         int a
     }
}'

    Database can be queried/updated with cdb2sql:

    cdb2sql mikedb local 'insert into t1(a) values(1)'
(rows inserted=1)
cdb2sql mikedb local 'select * from t1'
(a=1)