Hello;

 

Each chaincode language uses a 'natural-to-the-language' logging library, eg java.util.Logging or winston.  The user's implementation likewise can hook into these libraries. 

For a typical K8S deployment the logs will be written to STDOUT to be picked up the tooling of your choice.  

 

There's no in-built mechanism to store the logs or hashes on ledger..  Though that it self could be coded in a separate chaincode. 

 

 

Regards, Matthew.

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Matthew B White  IBM Blockchain Solutions Architect

 

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----- Original message -----
From: "Santiago Figueroa Lorenzo" <santiagofigueroalorenzo@...>
Sent by: fabric@...
To: fabric@...
Cc:
Subject: [EXTERNAL] [Hyperledger Fabric] Chaincode logs
Date: Wed, Feb 10, 2021 8:47 PM
 

Hi Fabric experts,

I am attempting to develop a methodology to retrieve logs from the chaincode, in order to visualize in Kibana through ELK infrastructure. At the moment, I am retrieving chaincode logs using the logrus (https://github.com/sirupsen/logrus) library. As part of the log is included relevant information such as channel id, chaincode name, method implemented and the type of log (information, error, etc). For instance:


 

In this regards, I have two questions:

1. Is there another more efficient way to retrieve logs?

2. Although the information at the time of retrieval is reliable (from chaincode container), with this method, once the data are in transit to Kibana I would have no way to trust on this data. Is there some mechanism, similar to what Ethereum does with its events, that allows to leave some mark in the ledger for these logs?


Thanks in advance,

Santiago.
 

 

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