21.02.2020

Review: Blockchain for dummies

The book "blockchain for dummies" provided by IBM contains 6 chapters on 41 pages. (Download from IBM)

The chapters 1 & 2 describe the basic of blockchain technology.
From my point of view, this part is a bit too shallow, because there is no single formular inside this book ;-)
But there are some nice illustrations given:

and the differences between a public blockchain and corporate blockchains are good explained including their  consequences.

Chapter 3 is about where companies can use blockchains. This chapter i did not understand. It is all about frictions which companies have to overcome. But these frictions are not special to blockchain (like "innovation restrictions").

In chapter 4 some examples are shown. These examples are very universal examples, which are too abstract in my eyes.

Chapter 5 contains information about a project of the Linux Foundation: Hyperledger.
This is very nice opening for https://www.hyperledger.org/.

Chapter 6 comes up with ten steps to your first blockchain application.
Skippable.

My conclusion: a very nice book and really ok for free. But I wouldn't spend any money on it...

31.01.2020

Oracle BPEL: What's up with it?

Nearly 20 years ago there was a new standard for modelling business processes: BPEL (https://en.wikipedia.org/wiki/Business_Process_Execution_Language)
Oracle bought Collaxa and released the Oracle BPEL Process Manager.
In 2009 i wrote some posts over tutorials, which where from collaxa and which were very useful for starting with Oracle BPEL product:
http://dietrichschroff.blogspot.com/search?q=lost+collaxa

And what is left today?

The product is still listed on Oracle homepage:

And there is a section with some "news":


But the version number 10.1.3.4 is not really somehing new and if you open the white paper you will see:

I think a whitepaper from 2014 is not really something new. 

If you take a look on the BPEL specification at oasis (http://docs.oasis-open.org/wsbpel/2.0/OS/wsbpel-v2.0-OS.html), you can see, that there was no update to the BPEL standard for more than 10 years. 

It is very sad, that this concept of modelling processes in a graphical way was unsuccessful...

25.01.2020

Oracle VM Server: OVMAPI_2005E and OVMEVT_003503D_000

In my OVM environment i was trying to delete a server from a pool and this did not work. The error i got signalled was:
OVMAPI_2005E "[ServerDbImpl] xx:yy:zz:... (oraclevm)" contains a component "xx:yy:zz:..." in error. Error event: server.cluster.failure., Summary: Server Cluster Failure, Description: Failed to leave cluster OVMEVT_003503D_000 Server reboot is required..
I rebootet the server: still the same error.
I rebootet the ovm manager: still the same error.

Then i realized, that there was a red cross at my server:

The solution was: Select events from the drop down for this server:

There i had to "Acknowledge" the events and after that i was able to remove the server without any further error...