在Postgresql中运行Cygnus的问题

Question

So I have installed Cygnus and in the simple test configuration case which I took from here ( https://github.com/telefonicaid/fiware-cygnus/blob/master/cygnus-ngsi/README.md ) everything works fine.

But I need Postgresql as a backend for my application. For this I adjusted the agent_1.conf file with all postgresql parameters found from http://fiware-cygnus.readthedocs.io/en/latest/cygnus-ngsi/installation_and_administration_guide/ngsi_agent_conf/

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

cygnus-ngsi.sources.http-source.channels = hdfs-channel mysql-channel ckan-channel mongo-channel sth-channel kafka-channel dynamo-channel 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.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.sinks.postgresql-sink.channel = postgresql-channel
cygnus-ngsi.sinks.postgresql-sink.type = com.telefonica.iot.cygnus.sinks.NGSIPostgreSQLSink
cygnus-ngsi.sinks.postgresql-sink.postgresql_host = 127.0.0.1
cygnus-ngsi.sinks.postgresql-sink.postgresql_port = 5432
cygnus-ngsi.sinks.postgresql-sink.postgresql_database = myUser
cygnus-ngsi.sinks.postgresql-sink.postgresql_username = mydb
cygnus-ngsi.sinks.postgresql-sink.postgresql_password = xxxx
cygnus-ngsi.sinks.postgresql-sink.attr_persistence = row
cygnus-ngsi.sinks.postgresql-sink.batch_size = 100
cygnus-ngsi.sinks.postgresql-sink.batch_timeout = 30
cygnus-ngsi.sinks.postgresql-sink.batch_ttl = 10

# postgresql-channel configuration
cygnus-ngsi.channels.postgresql-channel.type = memory
cygnus-ngsi.channels.postgresql-channel.capacity = 1000
cygnus-ngsi.channels.postgresql-channel.transactionCapacity = 100

I didn'r really find any information about other files I am supposed to change and aren't really sure if all parameters are correct. I also tried the sample configuration from here http://fiware-cygnus.readthedocs.io/en/latest/cygnus-ngsi/flume_extensions_catalogue/ngsi_postgresql_sink/index.html

Cygnus seems to start correctly but all if I try to send a notification I get connection refused

Answer 1

Befor doing anything, please, create the database, the user and the password in Postgresql.

The cygnus configuration is like this one. The /etc/cygnus/conf/cygnus_instance_1.conf file:

CYGNUS_USER=cygnus
CONFIG_FOLDER=/usr/cygnus/conf
CONFIG_FILE=/usr/cygnus/conf/agent_1.conf
AGENT_NAME=cygnus-ngsi
LOGFILE_NAME=cygnus.log
ADMIN_PORT=8081
POLLING_INTERVAL=30

So, the other file /usr/cygnus/conf/agent_1.conf is like this one (please change PostgreSQL parameters):

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.handler.events_ttl = 10
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

# =============================================
# postgresql-channel configuration
# channel type (must not be changed)
cygnus-ngsi.channels.postgresql-channel.type = memory
# capacity of the channel
cygnus-ngsi.channels.postgresql-channel.capacity = 1000
# amount of bytes that can be sent per transaction
cygnus-ngsi.channels.postgresql-channel.transactionCapacity = 100

# ============================================
# NGSIPostgreSQLSink configuration
# channel name from where to read notification events
cygnus-ngsi.sinks.postgresql-sink.channel = postgresql-channel
# sink class, must not be changed
cygnus-ngsi.sinks.postgresql-sink.type = com.telefonica.iot.cygnus.sinks.NGSIPostgreSQLSink
# true applies the new encoding, false applies the old encoding.
# cygnus-ngsi.sinks.postgresql-sink.enable_encoding = false
# true if the grouping feature is enabled for this sink, false otherwise
cygnus-ngsi.sinks.postgresql-sink.enable_grouping = false
# true if name mappings are enabled for this sink, false otherwise
cygnus-ngsi.sinks.postgresql-sink.enable_name_mappings = false
# true if lower case is wanted to forced in all the element names, false otherwise
# cygnus-ngsi.sinks.postgresql-sink.enable_lowercase = false
# the FQDN/IP address where the PostgreSQL server runs
cygnus-ngsi.sinks.postgresql-sink.postgresql_host = 127.0.0.1
# the port where the PostgreSQL server listens for incomming connections
cygnus-ngsi.sinks.postgresql-sink.postgresql_port = 5432
# the name of the postgresql database
cygnus-ngsi.sinks.postgresql-sink.postgresql_database = cygnusdb
# a valid user in the PostgreSQL server
cygnus-ngsi.sinks.postgresql-sink.postgresql_username = cygnus
# password for the user above
cygnus-ngsi.sinks.postgresql-sink.postgresql_password = cygnusdb
# how the attributes are stored, either per row either per column (row, column)
cygnus-ngsi.sinks.postgresql-sink.attr_persistence = row
# select the data_model: dm-by-service-path or dm-by-entity
cygnus-ngsi.sinks.postgresql-sink.data_model = dm-by-entity
# number of notifications to be included within a processing batch
cygnus-ngsi.sinks.postgresql-sink.batch_size = 1
# timeout for batch accumulation
cygnus-ngsi.sinks.postgresql-sink.batch_timeout = 30
# number of retries upon persistence error
cygnus-ngsi.sinks.postgresql-sink.batch_ttl = 0
# true enables cache, false disables cache
cygnus-ngsi.sinks.postgresql-sink.backend.enable_cache = true