Cryptocurrency Exchange Platform - OpenDAX

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Rango is part of OpenDAX Trading Platform


Rango is a general purpose websocket server which dispatch public and private messages from RabbitMQ. Rango is made as a drop-in replacement of Ranger built in ruby. It was designed to be very fast, scalable with a very low memory footprint.


To simplify the migration from Ranger all environement variables are the same:

RANGER_HOST0.0.0.0Hostname to expose the websocket connection
RANGER_PORT8080Websocket server port
RABBITMQ_HOSTlocalhostRabbitMQ hostname to connect to
RABBITMQ_PORT5672RabbitMQ port
RABBITMQ_USERguestUsername used to authenticate to RabbitMQ
RABBITMQ_PASSWORDguestPassword used to authenticate to RabbitMQ


Rango exposes metrics in Prometheus format on the port 4242.

Rango metrics

rango_hub_clients_countgaugeNumber of clients currently connected
rango_hub_subscriptions_countgaugeNumber of user subscribed to a topic

HTTP metrics

promhttp_metric_handler_requests_in_flightgaugeCurrent number of scrapes being served.
promhttp_metric_handler_requests_totalcounterTotal number of scrapes by HTTP status code.

Process metrics

process_cpu_seconds_totalcounterTotal user and system CPU time spent in seconds.
process_max_fdsgaugeMaximum number of open file descriptors.
process_open_fdsgaugeNumber of open file descriptors.
process_resident_memory_bytesgaugeResident memory size in bytes.
process_start_time_secondsgaugeStart time of the process since unix epoch in seconds.
process_virtual_memory_bytesgaugeVirtual memory size in bytes.
process_virtual_memory_max_bytesgaugeMaximum amount of virtual memory available in bytes.

Go standard metrics

go_gc_duration_seconds{quantile}summaryA summary of the pause duration of garbage collection cycles.
go_goroutinesgaugeNumber of goroutines that currently exist.
go_info{version}gaugeInformation about the Go environment.
go_memstats_alloc_bytesgaugeNumber of bytes allocated and still in use.
go_memstats_alloc_bytes_totalcounterTotal number of bytes allocated, even if freed.
go_memstats_buck_hash_sys_bytesgaugeNumber of bytes used by the profiling bucket hash table.
go_memstats_frees_totalcounterTotal number of frees.
go_memstats_gc_cpu_fractiongaugeThe fraction of this program's available CPU time used by the GC since the program started.
go_memstats_gc_sys_bytesgaugeNumber of bytes used for garbage collection system metadata.
go_memstats_heap_alloc_bytesgaugeNumber of heap bytes allocated and still in use.
go_memstats_heap_idle_bytesgaugeNumber of heap bytes waiting to be used.
go_memstats_heap_inuse_bytesgaugeNumber of heap bytes that are in use.
go_memstats_heap_objectsgaugeNumber of allocated objects.
go_memstats_heap_released_bytesgaugeNumber of heap bytes released to OS.
go_memstats_heap_sys_bytesgaugeNumber of heap bytes obtained from system.
go_memstats_last_gc_time_secondsgaugeNumber of seconds since 1970 of last garbage collection.
go_memstats_lookups_totalcounterTotal number of pointer lookups.
go_memstats_mallocs_totalcounterTotal number of mallocs.
go_memstats_mcache_inuse_bytesgaugeNumber of bytes in use by mcache structures.
go_memstats_mcache_sys_bytesgaugeNumber of bytes used for mcache structures obtained from system.
go_memstats_mspan_inuse_bytesgaugeNumber of bytes in use by mspan structures.
go_memstats_mspan_sys_bytesgaugeNumber of bytes used for mspan structures obtained from system.
go_memstats_next_gc_bytesgaugeNumber of heap bytes when next garbage collection will take place.
go_memstats_other_sys_bytesgaugeNumber of bytes used for other system allocations.
go_memstats_stack_inuse_bytesgaugeNumber of bytes in use by the stack allocator.
go_memstats_stack_sys_bytesgaugeNumber of bytes obtained from system for stack allocator.
go_memstats_sys_bytesgaugeNumber of bytes obtained from system.
go_threadsgaugeNumber of OS threads created.

#Start the server



In rango there are three stream scopes: public, private and prefixed.


Anyone can register to Public streams, even anonymous users, like orderbook updates, klines and tickers. AMQP message with routing key public.market_id.event (public.btcusd.trade) are routed as public messages.


With Private stream the user will receive only the message addressed to him, for example its own order updates or trades. AMQP messages with routing key private.UID.event (private.IDABC0000001.trade) are routed as private messages.


Prefixed stream scopes are restricted based on user role (RBAC). For example, a specific prefix can be configured so only users with role admin or superadmin will receive messages of this stream. AMQP message with routing key (prefix).market_id.event (admin.btcusd.sys) are routed as prefixed messages.

Configure RBAC prefix streams

To allow specific user roles to connect to prefixed stream, set RANGO_RBAC_EXAMPLE env, where EXAMPLE is the name of the prefix. Without this env, nobody will be allowed to subscribe. One specific environment variable should be set for each rbac stream.

For example you can configure the streams admin, sys and accounting as follow:

export RANGO_RBAC_ADMIN=admin,superadmin
export RANGO_RBAC_SYS=admin,superadmin,operator
export RANGO_RBAC_ACCOUNTING=accountant,operator

User with role 'accountant' will received messages with route accounting.asset.new for example.

#Connect to public channel

wscat --connect localhost:8080/public

#Connect to private channel

wscat --connect localhost:8080/private --header "Authorization: Bearer ${JWT}"


Subscribe to a stream list


Unsubscribe to one or several streams



Barong JWT is released under the terms of the Apache License 2.0.


Maintained by Openware and used in its cryptocurrency exchange software stack.