Created question in FIWARE Q/A platform on 10-03-2022 at 17:03
Please, ANSWER this question AT https://stackoverflow.com/questions/71428255/cygnus-does-not-persist-data-into-postsql

Question:
Cygnus does not persist data into PostSQL

Description:
I am using the following tutorial to persist data in a PostGresQL database via Cygnus.
https://documenter.getpostman.com/view/513743/RWEcR2DC
When using a MySQL database with Cygnus everything works fine as you can see below:
mysql> SHOW tables FROM openiot;
-------------------------------------------------------

-------------------------------------------------------

-------------------------------------------------------
109 rows in set (0.00 sec)

But when using PostGres as backend, the NGSIPostgreSQLSink does not create tables.
Here is my setup on docker:
postgres:
image: postgres:latest
hostname: postgres
expose:

• "5432"
  ports:
• "5432:5432"
  environment:
• "POSTGRES_PASSWORD=password"
• "POSTGRES_USER=postgres"
• "POSTGRES_DB=postgres"
  volumes:
• data-postgres:/var/lib/postgresql/data

cygnus:
image: fiware/cygnus-ngsi:latest
hostname: cygnus
depends_on:

• postgres
  expose:
• "5080"
  ports:
• "5055:5055"
• "5080:5080"
  environment:
• "CYGNUS_POSTGRESQL_HOST=postgres"
• "CYGNUS_POSTGRESQL_PORT=5432"
• "CYGNUS_POSTGRESQL_USER=postgres"
• "CYGNUS_POSTGRESQL_PASS=password"
• "CYGNUS_POSTGRESQL_ENABLE_CACHE=true"
• "CYGNUS_POSTGRESQL_SERVICE_PORT=5055"
• "CYGNUS_LOG_LEVEL=DEBUG"
• "CYGNUS_API_PORT=5080"
• "CYGNUS_SERVICE_PORT=5055"

If I list the schemas with a PostGres client there is no openiot schema:
postgres=# \dn
List of schemas
Name | Owner
-------+---------
public | postgres
(1 row)

I also tried to mount the following agent.conf and cygnus_instance.conf files in docker:
docker
volumes:

• ./conf/cygnus:/opt/apache-flume/conf/agent:ro

agent.conf
cygnus-ngsi.sources = http-source
cygnus-ngsi.sinks = postgresql-sink
cygnus-ngsi.channels = postgresql-channel

cygnus-ngsi.sources.http-source.channels = postgresql-channel
cygnus-ngsi.sources.http-source.type = org.apache.flume.source.http.HTTPSource
cygnus-ngsi.sources.http-source.port = 5050
cygnus-ngsi.sources.http-source.handler = com.telefonica.iot.cygnus.handlers.NGSIRestHandler
cygnus-ngsi.sources.http-source.handler.notification_target = /notify
cygnus-ngsi.sources.http-source.handler.default_service = default
cygnus-ngsi.sources.http-source.handler.default_service_path = /
cygnus-ngsi.sources.http-source.interceptors = ts gi
cygnus-ngsi.sources.http-source.interceptors.ts.type = timestamp
cygnus-ngsi.sources.http-source.interceptors.gi.type = com.telefonica.iot.cygnus.interceptors.NGSIGroupingInterceptor$Builder
cygnus-ngsi.sources.http-source.interceptors.gi.grouping_rules_conf_file = /usr/cygnus/conf/grouping_rules.conf
cygnus-ngsi.sources.http-source.interceptors.nmi.type = com.telefonica.iot.cygnus.interceptors.NGSINameMappingsInterceptor$Builder
cygnus-ngsi.sources.http-source.interceptors.nmi.name_mappings_conf_file = /usr/cygnus/conf/name_mappings.conf

cygnus-ngsi.sinks.postgresql-sink.channel = postgresql-channel
cygnus-ngsi.sinks.postgresql-sink.type = com.telefonica.iot.cygnus.sinks.NGSIPostgreSQLSink
cygnus-ngsi.sinks.postgresql-sink.enable_encoding = false
cygnus-ngsi.sinks.postgresql-sink.enable_name_mappings = false
cygnus-ngsi.sinks.postgresql-sink.enable_grouping = false
cygnus-ngsi.sinks.postgresql-sink.enable_lowercase = false
cygnus-ngsi.sinks.postgresql-sink.postgresql_host = postgres
cygnus-ngsi.sinks.postgresql-sink.postgresql_port = 5432
cygnus-ngsi.sinks.postgresql-sink.postgresql_database = postgres
cygnus-ngsi.sinks.postgresql-sink.postgresql_username = postgres
cygnus-ngsi.sinks.postgresql-sink.postgresql_password = password
cygnus-ngsi.sinks.postgresql-sink.attr_persistence = column
cygnus-ngsi.sinks.postgresql-sink.data_model = by-service-path
cygnus-ngsi.sinks.postgresql-sink.batch_size = 100
cygnus-ngsi.sinks.postgresql-sink.batch_timeout = 30
cygnus-ngsi.sinks.postgresql-sink.batch_ttl = 10
cygnus-ngsi.sinks.postgresql-sink.persist_errors = true

cygnus-ngsi.channels.postgresql-channel.type = memory
cygnus-ngsi.channels.postgresql-channel.capacity = 100000
cygnus-ngsi.channels.postgresql-channel.transactionCapacity = 10000

cygnus_instance.conf
CYGNUS_USER=cygnus
CONFIG_FOLDER=/usr/cygnus/conf
CONFIG_FILE=/usr/cygnus/conf/agent.conf
AGENT_NAME=cygnusagent
LOGFILE_NAME=cygnus.log
ADMIN_PORT=8081
POLLING_INTERVAL=30

But to no avail Cygnus is still not persisting data in PostGres.
Here are some logs from the Cygnus service:
time=2022-03-10T17:02:12.429Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineOperation | msg=org.eclipse.jetty.jmx.ObjectMBean[809] : defineOperation start false:ACTION:Starts the instance

time=2022-03-10T17:02:12.429Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineOperation | msg=org.eclipse.jetty.jmx.ObjectMBean[863] : Method Cache: start()

time=2022-03-10T17:02:12.429Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=getMBeanInfo | msg=org.eclipse.jetty.jmx.ObjectMBean[318] : Method Annotation found for: stop

time=2022-03-10T17:02:12.429Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineOperation | msg=org.eclipse.jetty.jmx.ObjectMBean[809] : defineOperation stop false:ACTION:Stops the instance

time=2022-03-10T17:02:12.430Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineOperation | msg=org.eclipse.jetty.jmx.ObjectMBean[863] : Method Cache: stop()

time=2022-03-10T17:02:12.431Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=getMBeanInfo | msg=org.eclipse.jetty.jmx.ObjectMBean[286] : Influenced by: org.eclipse.jetty.util.component.Container

time=2022-03-10T17:02:12.431Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=getMBeanInfo | msg=org.eclipse.jetty.jmx.ObjectMBean[291] : Annotations not found for: org.eclipse.jetty.util.component.Container

time=2022-03-10T17:02:12.431Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=getMBeanInfo | msg=org.eclipse.jetty.jmx.ObjectMBean[286] : Influenced by: org.eclipse.jetty.util.component.Destroyable

time=2022-03-10T17:02:12.432Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=getMBeanInfo | msg=org.eclipse.jetty.jmx.ObjectMBean[318] : Method Annotation found for: destroy

time=2022-03-10T17:02:12.432Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineOperation | msg=org.eclipse.jetty.jmx.ObjectMBean[809] : defineOperation destroy false:ACTION:Destroys this component

time=2022-03-10T17:02:12.432Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineOperation | msg=org.eclipse.jetty.jmx.ObjectMBean[863] : Method Cache: destroy()

time=2022-03-10T17:02:12.432Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=getMBeanInfo | msg=org.eclipse.jetty.jmx.ObjectMBean[286] : Influenced by: org.eclipse.jetty.util.component.Dumpable

time=2022-03-10T17:02:12.433Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=getMBeanInfo | msg=org.eclipse.jetty.jmx.ObjectMBean[318] : Method Annotation found for: dump

time=2022-03-10T17:02:12.433Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineOperation | msg=org.eclipse.jetty.jmx.ObjectMBean[809] : defineOperation dump false:INFO:Dump the nested Object state as a String

time=2022-03-10T17:02:12.433Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineOperation | msg=org.eclipse.jetty.jmx.ObjectMBean[863] : Method Cache: dump()

time=2022-03-10T17:02:12.433Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=getMBeanInfo | msg=org.eclipse.jetty.jmx.ObjectMBean[286] : Influenced by: org.eclipse.jetty.server.Handler

time=2022-03-10T17:02:12.433Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=getMBeanInfo | msg=org.eclipse.jetty.jmx.ObjectMBean[305] : Attribute Annotation found for: getServer

time=2022-03-10T17:02:12.433Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineAttribute | msg=org.eclipse.jetty.jmx.ObjectMBean[657] : defineAttribute server false:true:class org.eclipse.jetty.server.handler.ErrorHandler:the jetty server for this handler

time=2022-03-10T17:02:12.433Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineAttribute | msg=org.eclipse.jetty.jmx.ObjectMBean[729] : passed convert checks server for type class org.eclipse.jetty.server.Server

time=2022-03-10T17:02:12.434Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=getMBeanInfo | msg=org.eclipse.jetty.jmx.ObjectMBean[318] : Method Annotation found for: destroy

time=2022-03-10T17:02:12.434Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineOperation | msg=org.eclipse.jetty.jmx.ObjectMBean[809] : defineOperation destroy false:ACTION:destroy associated resources

time=2022-03-10T17:02:12.434Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=defineOperation | msg=org.eclipse.jetty.jmx.ObjectMBean[863] : Method Cache: destroy()

time=2022-03-10T17:02:12.434Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=beanAdded | msg=org.eclipse.jetty.jmx.MBeanContainer[208] : Registered org.eclipse.jetty.server.handler:type=errorhandler,id=0

time=2022-03-10T17:02:12.434Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=addBean | msg=org.eclipse.jetty.util.component.ContainerLifeCycle[322] : org.eclipse.jetty.server.Server@52e18a5d added

time=2022-03-10T17:02:12.436Z | lvl=INFO | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=doStart | msg=org.eclipse.jetty.server.Server[372] : jetty-9.4.6.v20170531

time=2022-03-10T17:02:12.471Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=doStart | msg=org.eclipse.jetty.server.handler.AbstractHandler[110] : starting org.eclipse.jetty.server.Server@52e18a5d

time=2022-03-10T17:02:12.471Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=setStarting | msg=org.eclipse.jetty.util.component.AbstractLifeCycle[185] : starting qtp260686092

time=2022-03-10T17:02:12.488Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=setStarted | msg=org.eclipse.jetty.util.component.AbstractLifeCycle[177] : STARTED @1893ms qtp260686092

time=2022-03-10T17:02:12.488Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=beanAdded | msg=org.eclipse.jetty.jmx.MBeanContainer[131] : beanAdded ServerConnector@cc1c486

->qtp260686092

time=2022-03-10T17:02:12.489Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=beanAdded | msg=org.eclipse.jetty.jmx.MBeanContainer[131] : beanAdded ServerConnector@cc1c486

->org.eclipse.jetty.util.thread.ScheduledExecutorScheduler@36176a5b

ing | msg=org.eclipse.jetty.util.component.AbstractLifeCycle[185] : starting o.e.j.s.ServletContextHandler@30833221

time=2022-03-10T17:02:12.551Z | lvl=DEBUG | corr=N/A | trans=N/A | srv=N/A | subsrv=N/A | comp=cygnus-ngsi | op=<clinit> | msg=org.eclipse.jetty.http.PreEncodedHttpField[64] : HttpField encoders loaded: [org.eclipse.jetty.http.Http1FieldPreEncoder@5b3a334b]

Thanks in advance.