Joins With Kafka

Florian Trossbach and Matthias J Sax show the various sorts of joins offered in Kafka, both streams and tables:

Apache Kafka’s Streams API provides a very sophisticated API for joins that can handle many use cases in a scalable way. However, some join semantics might be surprising to developers as streaming join semantics differ from SQL semantics. Furthermore, the semantics of changelog streams and tombstone messages (that are used for deletes) are a new concept in stream processing.

Kafka’s journey from Pub/Sub broker to distributed streaming platform is well underway, and our times as engineers are very exciting!

I didn’t know you could join streams together in Kafka, so that’s really cool.

Clearing Cached Credentials With Powershell

Adam Bertram shows how to use Powershell and cmdkey to clear out cached credentials:

It is even easier to use cmdkey with PowerShell. IT can build a small wrapper script that can manage cached credentials on one remote computer at a time and perform the action just as quickly on multiple computers at once.

The following example uses a PowerShell module called PSCredentialManager. IT pros can download the module from the PowerShell Gallery by running Install-Module.

Read the whole thing.

Rounding Up The Usual Suspects

Arun Sirpal shows us the suspect pages table in msdb:

Did you know that SQL Server tracks suspect pages and puts the details into the msdb database in a table called suspect_pages? Well it does, but the question I want answering is what happens if the page within the suspect pages table is fixed? Does it automatically get removed/updated or do we as the administrators have to do anything manually?

Let’s find out.

It’s a useful table to monitor.

Transactional Replication And SQL On Linux

Phil Grayson shows a way to get transactional replication working on Linux:

Microsoft have stated that transactional replication isn’t supported on Linux and we’re not sure if they intend to in the future. This means that if you try to add the server to a publisher, you get the following message. So you can’t use the GUI and it also means that you can’t use pull as the necessary files won’t be there.

Despite that warning, there is a way to set up a push subscription; click through for that way.

Polybase And RPC Protection

Casey Karst announces that Polybase supports Hadoop RPC protection:

Supporting this configuration allows PolyBase to connect and query Hadoop clusters that have wire encryption turned on. This enables a secure connection between Hadoop and SQL Server; as well as, among the Hadoop Data Nodes.

To connect to a Hadoop cluster with the hadoop.rpc.protection set to privacy or integrity, you will need to alter the core-site.xml file that is installed with PolyBase. This file is generally found at C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\Binn\Polybase\Hadoop\conf.

That’s good news for Polybase users.

Categories

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