README

Fork of csync2 Notes
====================
This has been my fork of csync2, which until haven't been public. 
I have been using csync2 for many years to sync my cluster of tiny linux machines 
(geographical distributed), as well as between macs. 

While distributed / cluster file systems is of great interest;
I have tried both GlusterFS and Ceph; I prefer the loosly coupled 
of csync2, and I can live with manual fixing replication problem once in a while 

I did my first patches for csync2 in 2010, and suggested some ideas around
furture development without getting any feedback I decided to continue on my own.

Difference from LINBIT are many. Many code cleanups, but also new features: 

- Attempting to track FS operations correct to eliminate redundant operations, 
- Extended with a MOVE operation. Detect it locally and perform it on peers
- Supporting hardlinks (with bugs)
- Implement a Storage layer so it could be extended with NoSQL storages
- SQL Layer that implements SQL common between SQL "drivers"
- Much fewer global variables that prevented multiple instance of connections 
  and threading
- Added tests to ensure functionality when refactoring 
- tail file method on inotify generated file to do FS changes without scan
- Begining of a "sync" tool that would fix inconsistencies

Broken stuff
============ 
- Database format has change. Now stored un-encoded. Only url encoded over wire
- Wire protocol: Minimal but minor things has changed. Dont use with older versions
- Windows support via CYGWIN has not been maintained and is for sure broken.
- Database creating is not 100% correct.
- sqlite 2/3 has not been tested for a long time. Mostly mysql, and some PostgreSQL

Building on macOS:
==================
The build system now automatically detects and handles macOS-specific issues.

Quick Setup (Recommended):
--------------------------
1. Run the macOS setup script:
   ./setup-macos.sh

2. Source the environment:
   source setup-env.sh

3. Build normally:
   ./autogen.sh
   ./configure
   make

Manual Setup:
-------------
If you prefer manual setup, install dependencies via Homebrew:

   brew install autoconf automake libtool bison flex pkg-config
   brew install librsync gnutls openssl sqlite mysql-client postgresql

Then set up your environment to use Homebrew's bison (not the system one):
   export PATH="/opt/homebrew/opt/bison/bin:$PATH"  # Apple Silicon
   export PATH="/usr/local/opt/bison/bin:$PATH"     # Intel

The configure script will automatically detect bison capabilities and set
appropriate flags. No manual YACC setting is required anymore.


Future
======
- Implement inotity daemon

cheers
:-Dennis Schafroth

==========================================================================

ORIGINAL README (from last public 2.0-rc2)
==============
About csync2
============

Csync2 is a cluster synchronization tool. It can be used to keep files on
multiple hosts in a cluster in sync. Csync2 can handle complex setups with
much more than just 2 hosts, handle file deletions and can detect conflicts.

It is expedient for HA-clusters, HPC-clusters, COWs and server farms. If
you are looking for a tool to sync your laptop with your workstation, you
better have a look at Unison (http://www.cis.upenn.edu/~bcpierce/unison/)
too.

See http://oss.linbit.com/ for more information on csync2. The csync2
subversion tree can be found at http://svn.linbit.com/csync2/.


Copyright
=========

csync2 - cluster synchronization tool, 2nd generation
LINBIT Information Technologies GmbH <http://www.linbit.com>
Copyright (C) 2004, 2005  Clifford Wolf <clifford@clifford.at>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


Documentation
=============

The latest version of the csync2 documentation can be found online at

	http://www.clifford.at/papers/2005/csync2/paper.pdf

and is mirrored at

	http://oss.linbit.com/csync2/paper.pdf

You should definitely read the documentation before trying to setup csync2.

The TeX source of the paper (as well as some slides for csync2 presentations)
can be found at <http://www.clifford.at/papers/2005/csync2/>.

The csync2 releases also have a copy of the 'paper.pdf' file bundled in the
csync2 source tarball.


More Documentation
==================

Eric Liang wrote a nice step-by-step introductions for using csync2 on redhat
machines:

	http://zhenhuiliang.blogspot.com/2006/04/csync2-is-so-cool.html


Mailing List
============

There is a csync2 mailing list:

	http://lists.linbit.com/mailman/listinfo/csync2

It is recommended to subscribe to this list if you are using csync2 in
production environments.

Building csync2
===============

You'll need the GNU autotools and a C++ compiler toolchain (gcc/g++ or clang++)
for building csync2. This version has been migrated to C++17.

Dependencies:
- C++17 compatible compiler (GCC 7+, Clang 5+, or newer)
- GNU autotools (autoconf, automake, libtool)
- Bison 3.0+ (for -W option support, older versions work but with warnings)
- Flex
- pkg-config

Linux/General Build:
-------------------
First, run the autogen.sh script:

$ ./autogen.sh

Then run configure, use ./configure --help for more options:

$ ./configure

Then run make:

$ make

macOS Build:
-----------
For macOS, use the provided setup script for easier dependency management:

$ ./setup-macos.sh
$ source setup-env.sh
$ ./autogen.sh
$ ./configure
$ make

csync2 should be built now. Direct any questions to the csync2 mailing list
(see above).

- Johannes