FIX Antenna Replication tool (RT) is a utility for efficient
replication of FIX logs across networked computers. It is typically
used for FIX session recovery on a backup FIX engine. It is
deployed on the primary FIX engine (server - publisher) and backup
destination(s) (subscriber- client). RT uses a custom transfer
protocol to synchronize FIX logs between the primary and backups
hosts in real time. It can be started at any time to resynchronize
primary and backup FIX log files. It is highly optimized for high
throughput to transfer data from multiple log files and to
efficiently utilize bandwidth. RT comes with an Admin interface to
operate and monitor the state of replication process.
Main mode diagrams
There are two most commonly used Replication tool modes.
1. Disaster recovery mode
In this case, the Replication Tool is used to synchronize the
FIX logs between different datacenters to increase the fault
tolerance of the system. This usage is represented in the following
diagram.

The FIXAntenna-based application and Replication Tool are
deployed on two nodes in the different datacenters. At any given
time, one of them has the main role and handles all the traffic
(Node 1 on the diagram) while another is a backup (Node 2 on the
diagram). Node 1 runs the FIXAntenna-based application and
Replication Tool Server.
Node 2 runs Replication Tool Client. It connects to the server
and requests the last known messages from Node 2. Replication Tool
Server monitors the log files and sends the messages to Replication
Tool Client. When Replication Tool Client receives messages from
Replication Tool Server, it writes them to the files in the
FIXAntenna-based application.
If the primary Data Center goes offline, support personnel
switches Node 2 in the Disaster recovery site to the role of the
main mode, stop Replication Tool Client and start the
FIXAntenna-based application and Replication Tool Server. The
FIXAntenna-based application sees the logs written earlier by the
Replication Tool Client and uses them to recover the FIX
sessions.
The clients need to reconnect and continue their FIX sessions.
Message replication between the datacenters is not synchronous, so
some client messages may be lost. Recovery of them is handled via
the FIX protocol retransmission starting from the sequence number
of the last processed (replicated) message.

When the primary site becomes available , Node 1 goes back
online in backup mode. It needs to get the messages that were
received/sent and handled by Node 2. Replication Tool Client
connects to Node 2 and requests the messages. First, it receives
the messages received and sent before Node 1 started; then, it
receives new messages as they are received or sent by the
FIXAntenna-based application on Node 2.
2. Multiple FIX logs replication
Replication tool allows configuration of multiple FIX log
storage in distinct computers.
Several instances of Replication tool subscriber can be
configured on distinct computers. Replication tool subscribers can
batch FIX logs from Replication tool publisher.

Administration
Admintool is used for Replication tool administration. Major
administration functions are:
- Show the list of all folders with their state and message
count
- Stop folder usage gracefully
- Renew stopped folder usage
- Check folder state (stopped or replicated)
- Stop folder usage immediately
- Stop folder usage immediately even if gracefully stop was
activated