#Guide |API Docs |Consulting |Community
Rango is part of OpenDAX Trading Platform
RANGO
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.
#Configuration
To simplify the migration from Ranger all environement variables are the same:
| VARIABLE | DEFAULT | DESCRIPTION |
|---|---|---|
| RANGER_HOST | 0.0.0.0 | Hostname to expose the websocket connection |
| RANGER_PORT | 8080 | Websocket server port |
| RABBITMQ_HOST | localhost | RabbitMQ hostname to connect to |
| RABBITMQ_PORT | 5672 | RabbitMQ port |
| RABBITMQ_USER | guest | Username used to authenticate to RabbitMQ |
| RABBITMQ_PASSWORD | guest | Password used to authenticate to RabbitMQ |
#Metrics
Rango exposes metrics in Prometheus format on the port 4242.
Rango metrics
| METRIC | TYPE | DESCRIPTION |
|---|---|---|
| rango_hub_clients_count | gauge | Number of clients currently connected |
| rango_hub_subscriptions_count | gauge | Number of user subscribed to a topic |
HTTP metrics
| METRIC | TYPE | DESCRIPTION |
|---|---|---|
| promhttp_metric_handler_requests_in_flight | gauge | Current number of scrapes being served. |
| promhttp_metric_handler_requests_total | counter | Total number of scrapes by HTTP status code. |
Process metrics
| METRIC | TYPE | DESCRIPTION |
|---|---|---|
| process_cpu_seconds_total | counter | Total user and system CPU time spent in seconds. |
| process_max_fds | gauge | Maximum number of open file descriptors. |
| process_open_fds | gauge | Number of open file descriptors. |
| process_resident_memory_bytes | gauge | Resident memory size in bytes. |
| process_start_time_seconds | gauge | Start time of the process since unix epoch in seconds. |
| process_virtual_memory_bytes | gauge | Virtual memory size in bytes. |
| process_virtual_memory_max_bytes | gauge | Maximum amount of virtual memory available in bytes. |
Go standard metrics
| METRIC | TYPE | DESCRIPTION |
|---|---|---|
| go_gc_duration_seconds{quantile} | summary | A summary of the pause duration of garbage collection cycles. |
| go_gc_duration_seconds_sum | ||
| go_gc_duration_seconds_count | ||
| go_goroutines | gauge | Number of goroutines that currently exist. |
| go_info{version} | gauge | Information about the Go environment. |
| go_memstats_alloc_bytes | gauge | Number of bytes allocated and still in use. |
| go_memstats_alloc_bytes_total | counter | Total number of bytes allocated, even if freed. |
| go_memstats_buck_hash_sys_bytes | gauge | Number of bytes used by the profiling bucket hash table. |
| go_memstats_frees_total | counter | Total number of frees. |
| go_memstats_gc_cpu_fraction | gauge | The fraction of this program's available CPU time used by the GC since the program started. |
| go_memstats_gc_sys_bytes | gauge | Number of bytes used for garbage collection system metadata. |
| go_memstats_heap_alloc_bytes | gauge | Number of heap bytes allocated and still in use. |
| go_memstats_heap_idle_bytes | gauge | Number of heap bytes waiting to be used. |
| go_memstats_heap_inuse_bytes | gauge | Number of heap bytes that are in use. |
| go_memstats_heap_objects | gauge | Number of allocated objects. |
| go_memstats_heap_released_bytes | gauge | Number of heap bytes released to OS. |
| go_memstats_heap_sys_bytes | gauge | Number of heap bytes obtained from system. |
| go_memstats_last_gc_time_seconds | gauge | Number of seconds since 1970 of last garbage collection. |
| go_memstats_lookups_total | counter | Total number of pointer lookups. |
| go_memstats_mallocs_total | counter | Total number of mallocs. |
| go_memstats_mcache_inuse_bytes | gauge | Number of bytes in use by mcache structures. |
| go_memstats_mcache_sys_bytes | gauge | Number of bytes used for mcache structures obtained from system. |
| go_memstats_mspan_inuse_bytes | gauge | Number of bytes in use by mspan structures. |
| go_memstats_mspan_sys_bytes | gauge | Number of bytes used for mspan structures obtained from system. |
| go_memstats_next_gc_bytes | gauge | Number of heap bytes when next garbage collection will take place. |
| go_memstats_other_sys_bytes | gauge | Number of bytes used for other system allocations. |
| go_memstats_stack_inuse_bytes | gauge | Number of bytes in use by the stack allocator. |
| go_memstats_stack_sys_bytes | gauge | Number of bytes obtained from system for stack allocator. |
| go_memstats_sys_bytes | gauge | Number of bytes obtained from system. |
| go_threads | gauge | Number of OS threads created. |
#Start the server
./rango
#Scopes
In rango there are three stream scopes: public, private and prefixed.
Public
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.
Private
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
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}"
#Messages
Subscribe to a stream list
{"event":"subscribe","streams":["eurusd.trades","eurusd.ob-inc"]}
Unsubscribe to one or several streams
{"event":"unsubscribe","streams":["eurusd.trades"]}
{"event":"subscribe","streams":["btcusd.trades","ethusd.ob-inc","ethusd.trades","xrpusd.ob-inc","xrpusd.trades","usdtusd.ob-inc","usdtusd.trades"]}
#License
Barong JWT is released under the terms of the Apache License 2.0.
#Credits
Maintained by Openware and used in its cryptocurrency exchange software stack.