# Copyright IBM Corp. All Rights Reserved.
#
# SPDX-License-Identifier: Apache-2.0
#

version: '2'

services:

  zookeeper:
    image: hyperledger/fabric-zookeeper
    restart: always
    ports:
      - '2181'
      - '2888'
      - '3888'

  kafka:
    image: hyperledger/fabric-kafka
    restart: always
    environment:
      # ========================================================================
      #     Reference: https://kafka.apache.org/documentation/#configuration
      # ========================================================================
      #
      # socket.request.max.bytes
      # The maximum number of bytes in a socket request. ATTN: If you set this
      # env var, make sure to update `brokerConfig.Producer.MaxMessageBytes` in
      # `newBrokerConfig()` in `fabric/orderer/kafka/config.go` accordingly.
      #- KAFKA_SOCKET_REQUEST_MAX_BYTES=104857600 # 100 * 1024 * 1024 B
      #
      # message.max.bytes
      # The maximum size of envelope that the broker can receive.
      - KAFKA_MESSAGE_MAX_BYTES=103809024 # 99 * 1024 * 1024 B
      #
      # replica.fetch.max.bytes
      # The number of bytes of messages to attempt to fetch for each channel.
      # This is not an absolute maximum, if the fetched envelope is larger than
      # this value, the envelope will still be returned to ensure that progress
      # can be made. The maximum message size accepted by the broker is defined
      # via message.max.bytes above.
      - KAFKA_REPLICA_FETCH_MAX_BYTES=103809024 # 99 * 1024 * 1024 B
      #
      # unclean.leader.election.enable
      # Data consistency is key in a blockchain environment. We cannot have a
      # leader chosen outside of the in-sync replica set, or we run the risk of
      # overwriting the offsets that the previous leader produced, and --as a
      # result-- rewriting the blockchain that the orderers produce.
      - KAFKA_UNCLEAN_LEADER_ELECTION_ENABLE=false
      #
      # log.retention.ms
      # Until the ordering service in Fabric adds support for pruning of the
      # Kafka logs, time-based retention should be disabled so as to prevent
      # segments from expiring. (Size-based retention -- see
      # log.retention.bytes -- is disabled by default so there is no need to set
      # it explicitly.)
      - KAFKA_LOG_RETENTION_MS=-1
    ports:
      - '9092'