Why? What? How?
nelsonic opened this issue · 51 comments
The home page https://temporal.io is a classic landing page ... tells me nothing
Lots of social proof: 🙄
This homepage has told me exactly zero of What I'm looking at or How it works. 🤦♂️
The hero text at the top of the Use Cases page https://temporal.io/use-cases is more social proof noise:
Keep scrolling and it's logos ...
At no point do they actually give any inkling what the actual use case might be!! 😡
Busy watching this: Designing a Workflow Engine from First Principles: https://youtu.be/t524U9CixZ0 📺 ⏳
Explaining Worflows, Task Queues ... ⏳
YouTube shortcut for speeding up playback > (Greater-than sign)
Most applications use databases for storing Task Queues:
Maxim has used the word "scalability" so many times in the last 10 minutes ... 🙄
Behind the scenes Temporal is using Elastic for storing data:
"Transfer queue mechanism" ...
Multicluster deployment:
i.e. paying for many instances ...
Wow. talk could have been 5 minutes. talk about dragging it out. 🙄
Next:
Complete Intro to Temporal Workshop - TypeScript SDK: https://youtu.be/CeHSmv8oF_4
Published Dec 4, 2021 ... 3 months ago. Is this even still relevant? Surely there are like 10 new frameworks since then!
Endorsement from Mitchell Hashimoto of Hashicorp:
Yah, it uses gRPC under the hood.
Suuuuuuuuuper scalable! 🚀
Workflows vs. Activities:
Basically nothing that has a side-effect is allowed in a workflow.
Loading ...
Good thing nobody is in a hurry. ⏳
While I wait ...
Watching this quick intro: https://youtu.be/2HjnQlnA5eY
https://github.com/temporalio/sdk-typescript 220 stars ... super popular.
Build failing.
https://github.com/temporalio/sdk-typescript/runs/5457647957?check_suite_focus=true
Bodes well.
Following the getting started guide: https://docs.temporal.io/docs/typescript/introduction/#getting-started
Bunch of warnings:
To begin development, start Temporal Server:
cd ~/path/to/temporal/docker-compose/
docker-compose up
If you haven’t run Temporal Server before, visit:
https://docs.temporal.io/docs/typescript/getting-started/
Then, in the project directory, using two other shells, run these commands:
npm run start.watch
npm run workflow
Got the following error:
[nodemon] starting `ts-node src/worker.ts`
Found prebuilt bridge module {
binary: '/Users/n/code/learn-temporal/example/node_modules/@temporalio/core-bridge/releases/x86_64-apple-darwin/index.node'
}
[TransportError: Server connection error: tonic::transport::Error(Transport, hyper::Error(Connect, ConnectError("tcp connect error", Os { code: 61, kind: ConnectionRefused, message: "Connection refused" })))]
[nodemon] app crashed - waiting for file changes before starting...
https://temporalio-samplestypesc-kf9hweoq2a6.ws-eu34.gitpod.io/
Hello World Walkthrough in TypeScript:
https://docs.temporal.io/docs/typescript/hello-world/
I can certainly see the benefits Temporal.
But the learning curve is steep ...
The temporal forum has only 3 threads for the typescript-sdk tag:
https://community.temporal.io/tag/typescript-sdk
Not very active ... 💭
"a real life production deployment can have 5 Frontend, 15 History, 17 Matching, and 3 Worker services per cluster."
https://docs.temporal.io/docs/concepts/what-is-a-temporal-cluster
https://docs.temporal.io/docs/concepts/what-is-a-temporal-cluster#database
Cassandra, MySQL, and PostgreSQL schemas are supported and thus can be used as the Server's database.
So at the heart of Temporal is a database.
Inevitably most people will use Cassandra because it's soooo scalable ...
https://en.wikipedia.org/wiki/Apache_Cassandra
Gitpod timed out:
Reloading ...
It didn't save my state ... 🙄
Starting everything again from scratch.
Going to try and run everything on localhost instead.
Installing docker ... ⏳
Still blows my mind that this app is so ridiculously huge!! 🤯
Read this while waiting ... https://docs.temporal.io/docs/server/production-deployment/
Of course it does ...
$ docker-compose up
Error response from daemon: dial unix /Users/n/Library/Containers/com.docker.docker/Data/docker.raw.sock: connect: no such file or directory
Trying to run the sample container:
docker run -d -p 80:80 docker/getting-started
Seeing:
Unable to find image 'docker/getting-started:latest' locally
latest: Pulling from docker/getting-started
59bf1c3509f3: Pull complete
8d6ba530f648: Pull complete
5288d7ad7a7f: Pull complete
39e51c61c033: Pull complete
ee6f71c6f4a8: Pull complete
f2303c6c8865: Pull complete
0645fddcff40: Pull complete
d05ee95f5d2f: Pull complete
Digest: sha256:aa945bdff163395d3293834697fa91fd4c725f47093ec499f27bc032dc1bdd16
Status: Downloaded newer image for docker/getting-started:latest
64ba27e3e31ba2efe50f5f3a2a12ba5094686dab3cf1fbcb40def900de78065e
Fans running on my poor mac ...
Once Docker has successfully downloaded all its dependencies and booted the containers,
you should see something similar to the following in the Docker Desktop App:
Fun fact: The node_modules directory for the Hello World example in Temporal uses 473.7 MB (504.5 MB on disk) ...
You wouldn't want to have too many of these projects. 🙄
Attempting to run docker-compose up -d
Get the following error:
Creating network "temporal-network" with driver "bridge"
Creating temporal-elasticsearch ... error
Creating temporal-postgresql ...
ERROR: for temporal-elasticsearch Cannot create container for service elasticsearch: Conflict. The container name "/temporal-elasticsearch" is already in use by container "830fbd148bb1f4e3422901f7ab362f09b40219a
Creating temporal-postgresql ... error
ERROR: for temporal-postgresql Cannot create container for service postgresql: Conflict. The container name "/temporal-postgresql" is already in use by container "ed97ad218913ad6d2a2d5ac2fbd13a81e51d7250e002e4ec693b0f63a18d76bc". You have to remove (or rename) that container to be able to reuse that name.
ERROR: for elasticsearch Cannot create container for service elasticsearch: Conflict. The container name "/temporal-elasticsearch" is already in use by container "830fbd148bb1f4e3422901f7ab362f09b40219ae4d4e82abda8d3f99d36dd16e". You have to remove (or rename) that container to be able to reuse that name.
ERROR: for postgresql Cannot create container for service postgresql: Conflict. The container name "/temporal-postgresql" is already in use by container "ed97ad218913ad6d2a2d5ac2fbd13a81e51d7250e002e4ec693b0f63a18d76bc". You have to remove (or rename) that container to be able to reuse that name.
ERROR: Encountered errors while bringing up the project.
n@MBP docker-compose % docker-compose down --remove-orphans
Removing network temporal-network
n@MBP docker-compose % docker-compose up -d
Creating network "temporal-network" with driver "bridge"
Creating temporal-postgresql ...
Creating temporal-elasticsearch ... error
ERROR: for temporal-elasticsearch Cannot create container for service elasticsearch: Conflict. The contai
Creating temporal-postgresql ... error
e4d4e82abda8d3f99d36dd16e". You have to remove (or rename) that container to be able to reuse that name.
ERROR: for temporal-postgresql Cannot create container for service postgresql: Conflict. The container name "/temporal-postgresql" is already in use by container "ed97ad218913ad6d2a2d5ac2fbd13a81e51d7250e002e4ec693b0f63a18d76bc". You have to remove (or rename) that container to be able to reuse that name.
ERROR: for elasticsearch Cannot create container for service elasticsearch: Conflict. The container name "/temporal-elasticsearch" is already in use by container "830fbd148bb1f4e3422901f7ab362f09b40219ae4d4e82abda8d3f99d36dd16e". You have to remove (or rename) that container to be able to reuse that name.
ERROR: for postgresql Cannot create container for service postgresql: Conflict. The container name "/temporal-postgresql" is already in use by container "ed97ad218913ad6d2a2d5ac2fbd13a81e51d7250e002e4ec693b0f63a18d76bc". You have to remove (or rename) that container to be able to reuse that name.
ERROR: Encountered errors while bringing up the project.
Thankfully - or sadly depending on your view - this is an issue many people have faced before.
Google search surfaces the following thread: moby/moby#23371
Good thing Docker is so efficient and doesn't take up any space on your SSD ...
Ran:
docker container prune
Purged all the Docker Containers and re-created them to test how long it would take.
Obviously Docker only removed the volumes but not the downloaded dependencies so in actual fact they weren't "purged" at all.
docker ps
docker.errors.DockerException: Error while fetching server API version: ('Connection aborted.', FileNotFoundError(2, 'No such file or directory'))
[61540] Failed to execute script docker-compose
Had to delete the previous docker containers and re-create them. Then it worked.
This is hilarious, and also on the first page of Google for "learn temporal" :) Actually managed to get the darn thing setup after reading through your posts..