I know there are some questions on this website that asks the same questions. However the answer is never clear: In PBFT, why cant the replicas execute the requests after 2/3s have prepared? why i...

I just start reading about zookeeper. And I am getting confused about the data replication and data module. The ZooKeeper ensemble will contain multiple nodes(Machine) with one leader and others ...

this is really dumb but what does zookeeper do that raft doesn't - not talking about zab but zookeeper itself. I get raft does leader election etc. w servers but what's the point of zookeeper? is ...

How can a distributed system be consistent and available (CA)? Because I would argue when a network partition occurs, CA cannot be possible in a way where every node of the network, even the partio...

I've read a post saying that: We can not implement traditional transaction system like 2 phase commit in micro-services in a distributed environment. I agree completely with this. But it wou...

Elasticsearch is a distributed system. As per the CAP theorem, it can satisfy any 2 out of 3 properties. Which one is compromised in Elasticsearch?

I have always worked on mobile technologies and now I am stepping into backend systems, more specifically systems design. I keep coming across conflicting statements for the roles of api gate...

From what I understand, a message queue helps with inter-process communication, but it is limited to basically allow communication between only 2 applications? I'm asking this because for example M...

This is from Kubernetes documentation: Consistent and highly-available key value store used as Kubernetes' backing store for all cluster data. Does Kubernetes have a separate mechanism internally...

I follow this great blog. In this blog, the author has drawn a complete picture of all types of isolation and consistency and the relationship between them. But based on the Google's blog, there ...

In my understanding, a leader sends AppendEntries RPC to the followers, and if majority of followers return success, the leader will commit this entry. It will commit this entry by applying it to i...

I am currently reading about Distributed Systems and I am facing two different terms which are described in a similar manner: Replication and Redundancy. Can anyone explain each term in part?

I have been having trouble finding an example of what use cases are suitable for Vector Clocks and Version Vectors, and how they might differ. I understand that they largely work in the same way, w...

I would like to know if my understanding of Message Bus and Message Queue workings is correct. First thing first, I need to clear the naming, a service bus is used interchangeably with message bus...

I've seen multiple issue about the: RuntimeError: NCCL error in: /opt/conda/conda-bld/pytorch_1614378083779/work/torch/lib/c10d/ProcessGroupNCCL.cpp:825, unhandled cuda error, NCCL version 2.7.8 nc...

I am currently trying to understand Lamport timestamps. Consider two processes P1 (producing events a1, a2,...) and P2 (producing events b1, b2,...). Let C(e) denote the Lamport timestamp associate...

My understanding of consistent hashing is that you take a key space, hash the key and then mod by say 360, and place the values in a ring. Then you equally space nodes on that ring. You pick the no...

Vertical distribution : Distributed processing is equivalent to organizing a client-server application as a multitiered architecture . Place logically different components on different machines. H...

I have a directory tree working_dir\ main.py my_agent\ my_worker.py my_utility\ my_utils.py Code in each file is as follows """ main.py """ import os, sys sys.path.append(os.path.dirname(os...

In general, I want to understand in a distributed application - is the load balancer a single point of failure? I am not sure, but this can be an Apache load balancer or on top of that a device/har...

Phase 2. (a) If the proposer receives a response to its prepare requests (numbered n) from a majority of acceptors, then it sends an accept request to each of those acceptors for a proposal numbe...

We need a lightweight client based messaging solution. We used AMQP, RabbitMQ before, but in C++ we have problems. We would like to choose ZeroMQ with malamuteserver or MQTT ? Our IoT will p...

I was asked this question in an interview and was unable to answer it. How does FB messenger order the messages on user side when two messages are concurrent in order to avoid view difference in di...

I am trying to understand the difference between the following terms: Trace ID Correlation ID Both terms seem to be used as an identifier for searching related logs produced by multiple services,...

Hystrix, a Netflix API for latency and fault tolerance in complex distributed systems uses Bulkhead Pattern technique for thread isolation. Can someone please elaborate on it.