Introduction
LIGO-Virgo Alert System (LVAlert) igwn-alert(old repo) igwn-alert(git)
- The International Gravitational Wave Network Alert System (igwn-alert) is a notification service built on the Apache Kafka protocol and the pubsub extension.
- It is a higher-level modification of SCIMMA's hop-client to streamline receiving and responding to alerts from GraceDB.
- This package replaces the legacy LIGO LVAlert XMPP-based alert system.
- The API are compatible with Python 3
- Retirement of existing LVAlert service targeted for ~April 2022.
- In O4, we will use igwn-alert.
Install
- The latest version is 0.7.0 (2025/07/22)
conda install igwn-alert==0.7.0
- help
% igwn-alert -h usage: igwn-alert [-h] [--no-auth] [-g GROUP] [-c CONSUMER_GROUP] [-j] [-l {critical,error,warning,info,debug}] [-n NETRC] [-p PORT] [-r] [-s SERVER] [-t LISTEN_RETRIES] [-u USERNAME] [-w RETRY_WAIT] [-V] {listen,subscriptions,topics,unsubscribe,send} ... positional arguments: {listen,subscriptions,topics,unsubscribe,send} sub-command help listen Listen for igwn-alert messages and print them to stdout. subscriptions List your subscriptions topics List available pubsub topics unsubscribe Unsubscribe from one or more topics send publish contents of a file to a pubsub topic options: -h, --help show this help message and exit --no-auth If set, disable authentication. -g GROUP, --group GROUP GraceDB group name (e.g., gracedb, gracedb-playground) -c CONSUMER_GROUP, --consumer-group CONSUMER_GROUP Consumer group ID to use for consuming messages across sessions -j, --jsonpp Output pretty print json -l {critical,error,warning,info,debug}, --log {critical,error,warning,info,debug} Log level -n NETRC, --netrc NETRC netrc file (default: read from NETRC environment variable or ~/.netrc) -p PORT, --port PORT igwn-alert server port -r, --retry-on-fatal reconnect listener on fatal exceptions -s SERVER, --server SERVER igwn-alert server hostname -t LISTEN_RETRIES, --listen_retries LISTEN_RETRIES fatal reconnect retry attempts -u USERNAME, --username USERNAME User name (default: look up in auth.toml or .netrc) -w RETRY_WAIT, --retry_wait RETRY_WAIT fatal reconnect retry attempts -V, --version show program's version number and exit
Setting in advance on web
- The authentification between the client and the server is managed by SciMMA.
The first step is to make a SCiMMa account by visiting https://my.hop.scimma.org/.
- At this time, access to igwn-alert is limited to LIGO, Virgo, or KAGRA members.
After log-in https://my.hop.scimma.org/, by clicking Hopskotch and Create new credentials, the password for your account will be shown just once.
Adding Authentication in local
Run the hop command and enter the username and the password.
- Empty Hostname is fine.
hop auth add
Once you entered, the authentification credential is stored in ~/.config/hop/auth.toml .
Note that in the authentification credential is connected to conda environment. You can see the environment name in ~/.config/hop/auth.toml.
- If you make new conda environment, you should run
hop auth add --force
- If you make new conda environment, you should run
Usage in local
- Initially, no topic (you can consider channel) is registered to your account.
From https://my.hop.scimma.org/, please add channel (they call Add permission).
- This doesn't show anything.
% igwn-alert topics Topics for group gracedb associated with the current credential:
Receive alert from MDC (Mock Data Challenge) analysis
Follow instruction by Joe.
- If you set up properly, check the topics which you are subscribing.
% igwn-alert --group gracedb-playground topics Topics for group gracedb-playground associated with the current credential: mdc_superevent cbc_pycbc
- Launch the igwn-alert
% igwn-alert --g gracedb-playground listen
To see the MDC alert on gracedb (2022/02/09), visit gracedb-playground (Require log-in).