Connect Fiware IoT Agent to sharded MongoDB - mongodb

Question

I am using to following docker-compose file to setup my sharded MongoDB which has 3 shards, 3 config servers and 2 router instances:
version: "3.5"
services:
mongorsn1:
container_name: mongors1n1
hostname: mongors1n1
image: mongo
command: mongod --shardsvr --replSet mongors1 --dbpath /data/db --port 27017
ports:
- 27017:27017
expose:
- "27017"
environment:
TERM: xterm
volumes:
- /etc/localtime:/etc/localtime:ro
- /mongo_cluster/data1:/data/db
mongors1n2:
container_name: mongors1n2
hostname: mongors1n2
image: mongo
command: mongod --shardsvr --replSet mongors1 --dbpath /data/db --port 27017
ports:
- 27027:27017
expose:
- "27017"
environment:
TERM: xterm
volumes:
- /etc/localtime:/etc/localtime:ro
- /mongo_cluster/data2:/data/db
mongors1n3:
container_name: mongors1n3
hostname: mongors1n3
image: mongo
command: mongod --shardsvr --replSet mongors1 --dbpath /data/db --port 27017
ports:
- 27037:27017
expose:
- "27017"
environment:
TERM: xterm
volumes:
- /etc/localtime:/etc/localtime:ro
- /mongo_cluster/data3:/data/db
mongocfg1:
container_name: mongocfg1
image: mongo
command: mongod --configsvr --replSet mongors1conf --dbpath /data/db --port 27017
environment:
TERM: xterm
expose:
- "27017"
volumes:
- /etc/localtime:/etc/localtime:ro
- /mongo_cluster/config1:/data/db
mongocfg2:
container_name: mongocfg2
image: mongo
command: mongod --configsvr --replSet mongors1conf --dbpath /data/db --port 27017
environment:
TERM: xterm
expose:
- "27017"
volumes:
- /etc/localtime:/etc/localtime:ro
- /mongo_cluster/config2:/data/db
mongocfg3:
container_name: mongocfg3
image: mongo
command: mongod --configsvr --replSet mongors1conf --dbpath /data/db --port 27017
environment:
TERM: xterm
expose:
- "27017"
volumes:
- /etc/localtime:/etc/localtime:ro
- /mongo_cluster/config3:/data/db
mongos1:
container_name: mongos1
image: mongo
hostname: mongos1
depends_on:
- mongocfg1
- mongocfg2
command: mongos --configdb mongors1conf/mongocfg1:27017,mongocfg2:27017,mongocfg3:27017 --port 27017
ports:
- 27019:27017
expose:
- "27017"
volumes:
- /etc/localtime:/etc/localtime:ro
mongos2:
container_name: mongos2
image: mongo
hostname: mongos2
depends_on:
- mongocfg1
- mongocfg2
command: mongos --configdb mongors1conf/mongocfg1:27017,mongocfg2:27017,mongocfg3:27017 --port 27017
ports:
- 27020:27017
expose:
- "27017"
volumes:
- /etc/localtime:/etc/localtime:ro
As you can see it is up and running correctly.
docker exec -it mongos1 bash -c "echo 'sh.status()' | mongo "
MongoDB shell version v4.4.6
connecting to: mongodb://127.0.0.1:27017/?compressors=disabled&gssapiServiceName=mongodb
Implicit session: session { "id" : UUID("f00e3ac7-e114-40b3-b7f8-0e5cf9c56e10") }
MongoDB server version: 4.4.6
--- Sharding Status ---
sharding version: {
"_id" : 1,
"minCompatibleVersion" : 5,
"currentVersion" : 6,
"clusterId" : ObjectId("609e21145937100b3f006e20")
}
shards:
{ "_id" : "mongors1", "host" : "mongors1/mongors1n1:27017,mongors1n2:27017,mongors1n3:27017", "state" : 1 }
active mongoses:
"4.4.6" : 2
autosplit:
Currently enabled: yes
balancer:
Currently enabled: yes
Currently running: no
Failed balancer rounds in last 5 attempts: 0
Migration Results for the last 24 hours:
No recent migrations
databases:
{ "_id" : "config", "primary" : "config", "partitioned" : true }
bye
Now here is the docker-compose file I use to connect Orion and the IoT Agent to my MongoDB shards.
version: "3.5"
services:
orion:
image: atos/smbt/orion:2.5.2
hostname: orion
container_name: orion
restart: unless-stopped
ports:
- "1026:1026"
entrypoint:
- /usr/bin/contextBroker
- -fg
- -multiservice
- -ngsiv1Autocast
- -corsOrigin
- __ALL
command: -dbhost mongors1n1:27017,mongors1n2:27027,mongors1n3:27037 -rplSet mongors1 -logLevel ERROR -noCache
healthcheck:
test: curl --fail -s http://orion:1026/version || exit 1
networks:
- fiware_mongo_sharding_default
iot-agent:
image: atos/smbt/iotagent-ul:1.15.0
hostname: iot-agent
container_name: iot-agent
restart: unless-stopped
expose:
- "4041"
- "7896"
ports:
- "4041:4041"
- "7896:7896"
environment:
- IOTA_CB_HOST=orion
- IOTA_CB_PORT=1026
- IOTA_NORTH_PORT=4041
- IOTA_REGISTRY_TYPE=mongodb
- IOTA_LOG_LEVEL=ERROR
- IOTA_TIMESTAMP=true
- IOTA_CB_NGSI_VERSION=v2
- IOTA_AUTOCAST=true
- IOTA_MONGO_HOST=mongors1n1
- IOTA_MONGO_PORT=27017
- IOTA_MONGO_DB=iotagentul
- IOTA_HTTP_PORT=7896
- IOTA_PROVIDER_URL=http://iot-agent:4041
networks:
- fiware_mongo_sharding_default
networks:
fiware_mongo_sharding_default:
external: true
Orion is connected to MongoDB but with the IoT Agent I get the following error message.
time=2021-05-14T07:51:51.086Z | lvl=ERROR | corr=28202651-30e1-48dc-88a9-53de603e7e6d | trans=28202651-30e1-48dc-88a9-53de603e7e6d | op=IoTAgentNGSI.DbConn | from=n/a | srv=n/a | subsrv=n/a | msg=MONGODB-001: Error trying to connect to MongoDB: MongoNetworkError: failed to connect to server [mongos1:27019] on first connect [MongoNetworkError: connect ECONNREFUSED 172.20.0.9:27019] | comp=IoTAgent
I have tried different things such as:
- IOTA_MONGO_HOST=mongos1
- IOTA_MONGO_PORT=27019
but to no avail unfortunately. Is there something I am doing wrong?
Thanks in advance for your help.

Answer 1

I found the solution myself. What I was doing wrong is that the IoT Agent should be NOT be connected with a Sharded MongoDB as it only expects one Mongo instance. That instance is used to persist and retrieve IoT device created when you provision a sensor via the IoT Agent. Device measurement are sent to the Orion Context Broket which will persist into the Sharded MongoDB. Hope it can help somebody else.