event-sourcing

问题 We got old legacy application with complex business logic which we need to rewrite. We consider to use cqrs and event sourcing. But it's not clear how to migrate data from the old database. Probable we need migrate it to the read database only, as we can't reproduce all the events to populate event store. But we atleast need to create some initial records in event store for each aggregate, like AggregateCreated ? Or we need write a scripts and to use all the commands one by one to recreate

问题 I am using Axon framework 4.0.3 with Spring Boot to have event sourcing, and have one tracking processor which is configured to have multiple segments/threads to process events concurrently: axon.eventhandling.processors[my_processor].initial-segment-count = 6 axon.eventhandling.processors[my_processor].thread-count = 3 It is meant to have 2 nodes of my_processor using 3 threads each. However, the problem with this solution is that it's not scalable. I have to know from the very beginning how

问题 I am using Axon framework 4.0.3 with Spring Boot to have event sourcing, and have one tracking processor which is configured to have multiple segments/threads to process events concurrently: axon.eventhandling.processors[my_processor].initial-segment-count = 6 axon.eventhandling.processors[my_processor].thread-count = 3 It is meant to have 2 nodes of my_processor using 3 threads each. However, the problem with this solution is that it's not scalable. I have to know from the very beginning how

问题 I am using kafka for event-sourcing. I realized that we still need to configure the log retention time, i.e. log.retention.hours . What is the best value to use if I want to keep all my messages indefinitely? The sample configuration for log.retention.bytes is set to -1, can I use -1 also in the log.retention.hours ? 回答1: See the following Kafka JIRA which is due for the 0.9.0.0 release. For the time being set as suggested: log.retention.bytes = -1 log.retention.hours = 2147483647 Which is

问题 I am using kafka for event-sourcing. I realized that we still need to configure the log retention time, i.e. log.retention.hours . What is the best value to use if I want to keep all my messages indefinitely? The sample configuration for log.retention.bytes is set to -1, can I use -1 also in the log.retention.hours ? 回答1: See the following Kafka JIRA which is due for the 0.9.0.0 release. For the time being set as suggested: log.retention.bytes = -1 log.retention.hours = 2147483647 Which is

问题 We are using CQRS and Event Sourcing using Axon 4. We have the following scenario. Domain Book Action- Create new Book into DB using the Axon CRQS and event sourcing flow (Command - Aggregate - Event) Action- Update the already created Book into DB using the Axon CRQS and event sourcing flow (Command - Aggregate - Event) In the Axon event store this two commands explained above (createCommand and updateCommand) have the same "aggregateIdentifier" id, they are in the same Aggregate tree,

问题 I'm currently designing a new enterprise system. The system's purpose is to track, display, and notify employees of customer's interactions (i.e. events) with the company. Using an event source pattern to keep a ledger of all the customer interactions/events being collected seems like a very good fit, since all of our additional domain objects are derived from the stream of events. However, I came across an article saying that a whole-system based off of event sourcing is an anti-pattern. Why

问题 I'm currently designing a new enterprise system. The system's purpose is to track, display, and notify employees of customer's interactions (i.e. events) with the company. Using an event source pattern to keep a ledger of all the customer interactions/events being collected seems like a very good fit, since all of our additional domain objects are derived from the stream of events. However, I came across an article saying that a whole-system based off of event sourcing is an anti-pattern. Why

问题 I'm currently designing a new enterprise system. The system's purpose is to track, display, and notify employees of customer's interactions (i.e. events) with the company. Using an event source pattern to keep a ledger of all the customer interactions/events being collected seems like a very good fit, since all of our additional domain objects are derived from the stream of events. However, I came across an article saying that a whole-system based off of event sourcing is an anti-pattern. Why

问题 I'm using a DDD/CQRS/ES approach and I have some questions about modeling my aggregate(s) and queries. As an example consider the following scenario: A User can create a WorkItem, change its title and associate other users to it. A WorkItem has participants (associated users) and a participant can add Actions to a WorkItem. Participants can execute Actions. Let's just assume that Users are already created and I only need userIds. I have the following WorkItem commands: CreateWorkItem