Gossip | Java实现的Gossip协议，借鉴CassandraV1.1.1源码 | Pub Sub library

In Cassandra vs Mongo debate, it is said that as mongo has master-slave architecture so it has a single point of failure(master) as when master fails, slave nodes take time to decide for new master, hence a window for downtime.

With Cassandra we don't have this problem as all nodes are equal. But then Cassandra too has a system wherein nodes use gossip protocol to keep themselves updated. In gossip protocol a minimum number of nodes are needed to take part. Suppose if one of the participating node goes down, then a new node needs to replace it. But it would take time to spawn a new replacement node, and this is a situation similar to master failure in mongo.

So what's the difference between 2 as far as single point of failure is concerned?

When run solana-test-validator it begins a new process with the following output:

1. Possibility to run asyncio coroutines.
2. Correct celery behavior on exceptions and task retries.
3. Possibility to use aioredis lock.

So, how to run async tasks properly to achieve the goal?

What is RuntimeError: await wasn't used with future (below), how can I fix it?

I have already tried:

async_to_sync (from asgiref https://pypi.org/project/asgiref/).

This option makes it possible to run asyncio coroutines, but retries functionality doesn't work.

(https://pypi.org/project/celery-pool-asyncio/)

Same problem as in asgiref. (This option makes it possible to run asyncio coroutines, but retries functionality doesn't work.)

I have performed try to create my own decorator like async_to_sync that runs coroutines threadsafe (asyncio.run_coroutine_threadsafe), but I have behavior as I described above.

Also I have try asyncio.run() or asyncio.get_event_loop().run_until_complete() (and self.retry(...)) inside celery task. This works well, tasks runs, retries works, but there is incorrect coroutine execution - inside async function I cannot use aioredis.

Implementation notes:

• start celery command: celery -A celery_test.celery_app worker -l info -n worker1 -P gevent --concurrency=10 --without-gossip --without-mingle
• celery app:

I have tried to make a redis cluster in k8s environment using "NodePort" type of service. More specifically, I want to compose a redis cluster across two different k8s cluster.

When I used LoadBalancer(External IP) for service type, cluster was made successfully. The problem is NodePort.

After I command redis-cli --cluster create, it stucks on "Waiting for the cluster to join"

Below is the logs of cluster create command. I deployed 4 leader pods and 4 slave pods with individual nodeport service.

So I had EventStore 5.0.7 installed as a 3 node cluster, working just fine.

I tried to upgrade to EventStore 21.10.1. The config for EventStore has changed substantially since the move from 5.x to 20.x and 21.x, and despite multiple readings of all kinds of documentation, I'm still doing something wrong.

What we see is 6 nodes appearing - each server twice - and the gossip failing, and nothing working, ie, cannot insert events.

What am I doing wrong?

EventStore 5.0.7

EventStore 21.10.1

Config for EventStore 21.10.1

I'm running a solana node using the solana-validator command (see Solana docs).

And I'd like to know if my validator is ready to connect to the http/rpc/ws port. What's the quickest way to do check to see if it's synced?

Currently, I'm using wscat to check to see if I can connect to the websocket, but am unable to. I'm not sure if that's because the node isn't setup right, or it's not synced, etc.

I know if I run solana gossip I should be able to see my IP in the list that populates... but is that the best way?

Celery disconnects from RabbitMQ each time a task is passed to rabbitMQ, however the task does eventually succeed:

My questions are:

1. How can I solve this issue?
2. What improvements can you suggest for my celery/rabbitmq configuration?

Celery version: 5.1.2 RabbitMQ version: 3.9.0 Erlang version: 24.0.4

RabbitMQ error (sorry for the length of the log:

i configured prometheus alertmanager no error in installation but systemctl status alertmanager.service gives

I have Celery running as a service on Ubuntu 20.04 with RabbitMQ as a broker.

Celery repeatedly restarts because it cannot access the RabbitMQ url (RABBITMQ_BROKER), a variable held in a settings.py outside of the Django root directory.

The same happens if I try to initiate celery via command line.

I have confirmed that the variable is accessible from within Django from a views.py print statement.

If I place the RABBITMQ_BROKER variable inside the settings.py within the Django root celery works.

My question is, how do I get celery to recognise the variable RABBITMQ_BROKER when it is placed in /etc/opt/mydjangoproject/settings.py?

My celery.py file: