In my project I have PostgreSQL database as main DB and I need to keep synchronized my neo4j DB. To do so I want to use Debezium for CDC, kafka and neo4j streams plugin. One of the reasons I prefer Debezium to jdbc is because it's real time. So at this point I want to get
PostgreSQL -> Debezium -> Kafka -> Confluent -> Neo4j
from documentation I found sink Neo4j CDC but only from another Neo4j DB.
Sink ingestion strategies
Change Data Capture Event
This method allows to ingest CDC events coming from another Neo4j Instance.
Why only from another Neo4j instance? I am confused because I don't understand how exactly I should implement Change data Capture from PostgreSQL to neo4j.
Related
I'm investigating the feasibility of using ksql db to filter out empty struct fields in kafka records in avro format then dump records to s3 in parquet format - removing all empty records in avro required in transforming to parquet.
Ksql can handle the filtering part in a very straightforward way. My questions is how I can connect ksql to minio.
Using kafka connector would require ksql db to write back to kafka under a new topic?
I also heard ksql has built-in connectors, not sure how it works.
I want to insert/update the document in Couchbase from their it should be automatically inserted/updated to neo4j database. Is their any plugin or software to do the same? How can I achieve this functionality?
Couchbase enterprise version: 6.6
Neo4j enterprise version: 4.1.3
I read this blog https://dzone.com/articles/couchbase-amp-jdbc-integrations-for-neo4j-3x but I am not getting clarity over Neo4jJSON Loader, please guide me for the same.
You could also use the Couchbase Eventing Service which will respond to any mutation and trigger a fragment of JavaScript code. Refer to https://docs.couchbase.com/server/current/eventing/eventing-overview.html
Now you would probably want to utilize something similar to the code in this scriptlet example: https://docs.couchbase.com/server/current/eventing/eventing-handler-curl-post.html provided that the Neo4j REST API has a sub 1 ms performance and honors KeepAlive a 12 physical core system could stream about 40K inserts (or updates) per second from Couchbase to your Neo4j instance.
You can use the Couchbase Kafka connector to send CDC events to Kafka.
https://docs.couchbase.com/kafka-connector/current/quickstart.html
From there, you can read the kafka topics in order to import the data into Neo4j :
https://github.com/neo4j-contrib/neo4j-streams
While creating some basic workflow using KNIME and PSQL I have encountered problems with selecting proper node for fetching data from db.
In node repo we can find at least:
PostgreSQL Connector
Database Reader
Database Connector
Actually, we can do the same using 2) alone or connecting either 1) or 2) to node 3) input.
I assumed there are some hidden advantages like improved performance with complex queries or better overall stability but on the other hand we are using exactly the same database driver, anyway..
There is a big difference between the Connector Nodes and the Reader Node.
The Database Reader, reads data into KNIME, the data is then on the machine running the workflow. This can be a bad idea for big tables.
The Connector nodes do not. The data remains where it is (usually on a remote machine in your cluster). You can then connect Database nodes to the connector nodes. All data manipulation will then happen within the database, no data is loaded to your machine (unless you use the output port preview).
For the difference of the other two:
The PostgresSQL Connector is just a special case of the Database Connector, that has pre-set configuration. However you can make the same configuration with the Database Connector, which allows you to choose more detailed options for non standard databases.
One advantage of using 1 or 2 is that you only need to enter connection details once for a database in a workflow, and can then use multiple reader or writer nodes. I'm not sure if there is a performance benefit.
1 offers simpler connection details with the bundled postgres jdbc drivers than 2
We are developing our own Informix Replication handler. Informix version is 12.10. We are using Enterprise Replication, Primary-Target One-to-many option. ie... all database changes originate at the primary
database and are replicated to the target databases. We configured replication setup and replication is working fine.
Now if we write into master server, it will replicate in to slaves. The problem is we are also able to write into slaves. Is there any way to make the slaves read only? ie.. We should only be able to write into master server. Is it possible?
Please note that we are not considering Update-Anywhere Replication System, since we are using Timeseries data and there are many restrictions in informix for Conflict resolution rules for timeseries data. So please dont suggest Update-Anywhere Replication.
You need to change the mode of the participants (slaves) to readonly.
Use this command:
cdr modify server --mode readonly <server_group>
Refer to the Informix Enterprise Replication documentation here
I am trying to setup a simple distributed application using erlang riak core framework. I read the documentation and it says I have to manually join the nodes via riak admin commands. I wanted to know what would happen if the entire cluster goes down.Do i need to have logic in my code to do a join on nodes every time cluster starts up or if there is a way to enlist all the nodes in a config?
When the nodes restart, they try to reconnect automatically, because when you joined some nodes with the command
riak_core:join("dev_1#127.0.0.1")
the data is saved locally to the node. If you want remove a node from cluster you should call
riak_core:leave()