Date   

Re: Storage data in private data collection has a different value #fabric #couchdb

Mark Lewis
 

I'll say first that this is not something I have experimented with myself. Private data values are put and retrieved using the ChaincodeStub as byte-array or string data, whereas what you're presenting is JSON, which I guess is what you are seeing in CouchDB? Do you have a minimal example chaincode implementation that demonstrates how you are putting and getting the private data that can be used to reproduce the problem? If so, it might be worth creating an issue to report a potential bug.


Re: Listening to events -fabric client java

Mark Lewis
 

If you just want to get chaincode events, you would be better to just listen directly for chaincode events:


The Fabric Gateway client API provides by far the most efficient Java client implementation of both block and chaincode eventing.

I would encourage you to avoid using fabric-sdk-java and prefer one of the high-level APIs above depending on the version of Fabric you are targeting. If you really must use the low-level legacy SDK for some reason, it provides chaincode event listening with Channel.registerChaincodeEventListener().

If you want to do the work yourself of extracting chaincode events from block events using the low-level legacy SDK, the block events you receive from fabric-sdk-java are the same as the ones surfaced by fabric-gateway-java, and you can listen for them using Channel.registerBlockListener(). Just be aware that you may receive duplicate or out-of-order events using fabric-sdk-java.

fabric-sdk-java provides very weak support for replay of events. The recommended approach is to create a new channel, remove all the peers and then re-add them to the channel with their peer options modified to specify an event start block. If you want to pick apart how fabric-gateway-java does this on top of fabric-sdk-java, the code is here:

https://github.com/hyperledger/fabric-gateway-java/blob/00afa0c6a376feea492b9d9390ae9415b404289d/src/main/java/org/hyperledger/fabric/gateway/impl/event/ReplayListenerSession.java#L31-L71


Re: Storage data in private data collection has a different value #fabric #couchdb

Joao Antunes
 

Any ideas regarding this error?


Now: Private Chaincode Lab - 10/25/2022 #cal-notice

Group Notification <noreply@...>
 

Private Chaincode Lab

When:
10/25/2022
8:00am to 9:00am
(UTC-07:00) America/Los Angeles

Where:
https://zoom.us/my/hyperledger.community.3?pwd=UE90WHhEaHRqOGEyMkV3cldKa2d2dz09

Organizer: Marcus Brandenburger bur@...

View Event

Description:
Two of the Hyperleger Labs projects (private data objects and private chain code) are collaborating to develop a "private smart contracts" capability.

Join Zoom Meeting https://zoom.us/j/5184947650?pwd=UE90WHhEaHRqOGEyMkV3cldKa2d2dz09 Meeting ID: 518 494 7650 Passcode: 475869


Re: Listening to events -fabric client java

Matthew White
 

Hello – yes I’ve got an example of that… somewhere…

 

I’ll push it a github repo as it’s a useful example

 

Thanks Matthew

 

From: fabric@... <fabric@...> On Behalf Of jeff.jo95z@...
Sent: 25 October 2022 10:05
To: fabric@...
Subject: [EXTERNAL] [Hyperledger Fabric] Listening to events -fabric client java

 

Hi, How to subscribe to block events in fabric client (java)? I was looking for an equivalent of this in fabric client: Consumer<BlockEvent> blockListener = blockEvent -> blockListenerProcess(); networkObj. addBlockListener(startBlockNumber,

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Hi,

How to subscribe to block events in fabric client (java)? 
 I was looking for an equivalent of this in fabric client:
      Consumer<BlockEvent> blockListener = blockEvent -> blockListenerProcess();
       networkObj.addBlockListener(startBlockNumber, blockListener);

Will it be possible to extract chaincode events from block events in this case?

In fabric gateway,we can use like this:

               blockEvent.getTransactionEvents()

               for (BlockEvent.TransactionEvent tEvent : transEvents) 

                  tEvent.getTransactionActionInfo(0).getEvent().getEventName()


Is it possible to do something similar in fabric client (java)?

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Listening to events -fabric client java

jeff.jo95z@...
 

Hi,

How to subscribe to block events in fabric client (java)? 
 I was looking for an equivalent of this in fabric client:
      Consumer<BlockEvent> blockListener = blockEvent -> blockListenerProcess();
       networkObj.addBlockListener(startBlockNumber, blockListener);

Will it be possible to extract chaincode events from block events in this case?

In fabric gateway,we can use like this:

               blockEvent.getTransactionEvents()

               for (BlockEvent.TransactionEvent tEvent : transEvents) 

                  tEvent.getTransactionActionInfo(0).getEvent().getEventName()


Is it possible to do something similar in fabric client (java)?


Workshop on Building Hyperledger Fabric Smart Contracts using Solidity and the EVM on Nov 3

David Boswell <dboswell@...>
 

You're welcome to join an online technical workshop run by Hyperledger Boston and The Blockchain Academy on Thursday Nov 3 at 8AM PDT.  The focus of the workshop will be how to build smart contracts for Hyperledger Fabric using Solidity & Fabric's Ethereum Virtual Machine.  Details are at:

Thanks,
David


Outstanding pull request to retire inactive maintainers

Ry Jones
 

Fabric has an outstanding pull request to retire inactive maintainers.
http://toc.hyperledger.org/inactivity.html


Re: Fabric client gateway service

Andrew Coleman
 

No, it's enabled by default.


Fabric client gateway service

jeff.jo95z@...
 

hi
In fabric 2.4 ,do we have to set any property for enabling gateway service?


Re: Fabric client java exception #fabric-sdk-java

jeff.jo95z@...
 

sorry
It was my mistake.Instead of group reply ,I clicked on reply to author


Re: Fabric client java exception #fabric-sdk-java

Mark Lewis
 

I notice that the code you mailed direct to me includes:

ManagedChannel grpcChannel = ManagedChannelBuilder.forAddress(gatewayUrl, gatewayPort)
        .usePlaintext()
        .build();

It is typical for a deployed Fabric network to use TLS connections, whereas your code is specifying a plain HTTP connection. This might be the cause of the connection failure. See the asset-transfer-basic sample for an example of configuring a TLS connection:

https://github.com/hyperledger/fabric-samples/blob/c323c9580717dd6376e5e2b07ecbb00af5b3bf00/asset-transfer-basic/application-gateway-java/src/main/java/App.java#L77-L84

Please send any follow-ups to the list, not directly to me.


Re: Fabric client java exception #fabric-sdk-java

Mark Lewis
 

It looks like a network communication failure between your client application and the Gateway service running in the peer. If it is a transient network failure then just re-submitting might work. If it persists then you might need to investigate the cause of the network issues.

One possibility is something along the route (like a firewall or ingress controller) terminating an idle connection. In these cases, setting appropriate keep-alive values on the gRPC  channel builder when creating the client connection that you pass to the Gateway connect can be helpful. See here for details on gRPC keep-alive:

https://github.com/grpc/grpc/blob/master/doc/keepalive.md


Fabric client java exception #fabric-sdk-java

jeff.jo95z@...
 

Hi ,

I was trying to submit a transaction via fabric client (java). I got the below exception:

org.hyperledger.fabric.client.EndorseException: io.grpc.StatusRuntimeException: UNAVAILABLE: Network closed for unknown reason

 I am using peer version 2.4
What maybe the reason for this?


Now: Fabric Contributor Meeting - 10/19/2022 #cal-notice

Group Notification <noreply@...>
 

Fabric Contributor Meeting

When:
10/19/2022
9:00am to 10:00am
(UTC-04:00) America/New York

Where:
https://zoom.us/my/hyperledger.community.3?pwd=UE90WHhEaHRqOGEyMkV3cldKa2d2dz09

Organizer: Dave Enyeart enyeart@...

View Event

Description:
For meeting agendas, recordings, and more details, see https://wiki.hyperledger.org/display/fabric/Contributor+Meetings

Join Zoom Meeting
https://zoom.us/j/5184947650?pwd=UE90WHhEaHRqOGEyMkV3cldKa2d2dz09
 
Meeting ID: 518 494 7650
Passcode: 475869


Fabric Contributor Meeting - October 19, 2022

David Enyeart
 

Hyperledger Fabric Contributor Meeting

When: Every 4th Wednesday 9am US Eastern, 13:00 UTC

Where: https://zoom.us/j/5184947650?pwd=UE90WHhEaHRqOGEyMkV3cldKa2d2dz09

Agendas and Recordings: https://wiki.hyperledger.org/display/fabric/Contributor+Meetings

 

Agenda for October 19, 2022

 

- Project status update

- Review Github board priorities - https://app.zenhub.com/workspaces/fabric-57c43689b6f3d8060d082cf1/board

- Discussion topics – ARM support, chaincode builder evolution

 

 


Now: Private Chaincode Lab - 10/18/2022 #cal-notice

Group Notification <noreply@...>
 

Private Chaincode Lab

When:
10/18/2022
8:00am to 9:00am
(UTC-07:00) America/Los Angeles

Where:
https://zoom.us/my/hyperledger.community.3?pwd=UE90WHhEaHRqOGEyMkV3cldKa2d2dz09

Organizer: Marcus Brandenburger bur@...

View Event

Description:
Two of the Hyperleger Labs projects (private data objects and private chain code) are collaborating to develop a "private smart contracts" capability.

Join Zoom Meeting https://zoom.us/j/5184947650?pwd=UE90WHhEaHRqOGEyMkV3cldKa2d2dz09 Meeting ID: 518 494 7650 Passcode: 475869


RFC for Byzantine Fault Tolerant ordering service - Final Comment Period

David Enyeart
 

The RFC for Byzantine Fault Tolerant ordering service https://github.com/hyperledger/fabric-rfcs/pull/52 has entered Final Comment Period. Please add any final comments to the RFC within the next week. If no material concerns are raised we will merge the RFC and start accepting pull requests for feature implementation with target delivery in Fabric v3.0.


Request for offchain couchdb tutorial for image data storage

m.memon725@...
 

Hello,

I wanted to ask if there is any HLF off-chain CouchDB data maintenance for storing image tutorials available.  I want to navigate the incoming image to off-chain DB rather than going to onchain CouchDB(for Hyperledger2.2). Basically for any invoked transaction scenario if the end-user wants to add information to the ledger that single transaction text is logged to the ledger along with the hashed reference to the image stored in off-chain CouchDB local instance. 
To set the context for question I have following links:
https://medium.com/@deeptiman/offchain-storage-in-hyperledger-fabric-77e28bd99e0c
https://stackoverflow.com/questions/49464591/what-is-the-best-way-of-image-storage-on-hyperledger-composer/49489574#49489574 


Hyperledger TOC Election Call for Nominations

David Boswell <dboswell@...>
 

This year's Hyperledger Technical Oversight Committee (TOC) election will happen from November 1 to 30, 2022.  Note that Hyperledger's Technical Steering Committee has recently been renamed to Technical Oversight Committee.

The election will include active contributors who have nominated themselves to run as candidates – check to see if you are eligible to run if you are unsure.  We are now opening the call for nominations and this process will go through October 31 at the end of the day Pacific time.

To nominate yourself use the following email template with the subject line "TOC election nomination" and send it to election-2022@...:

Dear Election Committee,

I nominate myself for the TOC election. My email address is <email> and my GitHub ID is <github id>.

The contributions that I have had to the Hyperledger Foundation in the past year are (please check all that apply)
- code contribution to project/lab
- maintainer of project/lab
- TOC Member
- Lab Steward
- SIG leader
- Task Force leader
- Other (please provide details)

Thanks,

<your name>

After you have emailed your nomination, please also create a nomination statement on the Hyperledger Github repo and include the following information: nominee name, short personal bio and a short personal pitch about why someone should consider voting for you.

If you have any questions about the election process, please feel free to write to election-2022@....

Thanks,

Hyperledger staff

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