User Story issue

[KaraMelih]

Description

The hop version 0.5.0 started to raise Network errors for me since this morning. Here is an example;

[description and details]

with stream.open("kafka://kafka.scimma.org/snews.experiments-firedrill", "r") as s: 
    for m in s:
    print(m) 

%3|1659366426.038|FAIL|rdkafka#consumer-2| [thrd:sasl_ssl://kafka.scimma.org:9092/bootstrap]: sasl_ssl://kafka.scimma.org:9092/bootstrap: Failed to connect to broker at [a.root-servers.net]:9092: Network is unreachable (after 41ms in state CONNECT)
Traceback (most recent call last):  
File "<stdin>", line 1, in <module> 
File "/home/kara-unix/anaconda3/envs/snews/lib/python3.9/site-packages/hop/io.py", line 119, in open

return Consumer( File "/home/kara-unix/anaconda3/envs/snews/lib/python3.9/site-packages/hop/io.py", line 299, in __init__  self.consumer.subscribe(topics) 
File "/home/kara-unix/anaconda3/envs/snews/lib/python3.9/site-packages/adc/consumer.py", line 41, in subscribe topic_meta = self.describe_topic(topic,  timeout) 
File "/home/kara-unix/anaconda3/envs/snews/lib/python3.9/site-packages/adc/consumer.py", line 63, in describe_topic  
cluster_meta = self._consumer.list_topics(timeout=timeout.total_seconds())

cimpl.KafkaException: KafkaError{code=_TRANSPORT,val=-195,str="Failed to get metadata: Local: Broker transport failure"}  >>>   >>> %3|1659366557.057|FAIL|rdkafka#consumer-2| [thrd:sasl_ssl://kafka.scimma.org:9092/bootstrap]: 

sasl_ssl://kafka.scimma.org:9092/bootstrap: Connect to ipv4#198.41.0.4:9092 failed: Connection timed out (after 130954ms in state CONNECT)   %3|1659366690.177|FAIL|rdkafka#consumer-2| [thrd:sasl_ssl://kafka.scimma.org:9092/bootstrap]: 
sasl_ssl://kafka.scimma.org:9092/bootstrap: Connect to ipv4#192.5.5.241:9092 failed: Connection timed out (after 132181ms in state CONNECT)    %3|1659366691.039|FAIL|rdkafka#consumer-2| [thrd:sasl_ssl://kafka.scimma.org:9092/bootstrap]: 
sasl_ssl://kafka.scimma.org:9092/bootstrap: Failed to connect to broker at [a.root-servers.net]:9092: Network is unreachable (after 43ms in state CONNECT) 

Definition of Done

I tried creating new credentials, I also tried using 3 different networks (which I was using in the past and it was working) including eduroam. Everything seems to be working, I seem to have a network connection. I do not understand why it started to crash

[KaraMelih]

I'm from Germany, and I set up all my accounts there.

Now I'm in US, last week it worked without any problems on my local machine when I was connected to eduroam. Today it started crashing, and just now I tried connecting to Germany via VPN and running it. It works.
I have no explanation, but I'm curious to learn why this might be.

[cnweaver]

Can you test whether the network(s) you're using have anyone blocking outgoing connections on the Kafka default port (9092), as this is disappointingly common? For example, you can test with a command like

echo 'test' | nc -w 10 kafka.scimma.org 9092; echo $?

which should print P0 fairly quickly if the port is not blocked, or take longer and print only 0 or 1 if the port is blocked.

[KaraMelih]

Hi yes, indeed this returns P0 only when I'm connected to VPN. And returns some error message when I'm connected to the local eduroam in Indiana. I can check the exact message tomorrow and post again if needed.
What is confusing is that I only started having this issue this week, I do not think I changed any network settings on my end.

[cnweaver]

Unfortunately, this is the type of thing that network admins change, sometimes in response to observing traffic. It may be possible to contact them and explain that there is a science use for having the port open.

[KaraMelih]

I was able to connect as long as I was using a VPN, however, today that also started rejecting my connection.
I'm first getting

%4|1659476487.055|TERMINATE|rdkafka#producer-1| [thrd:app]: Producer terminating with 1 message (293 bytes) still in 
 queue or transit: use flush() to wait for outstanding message delivery

Then it raises
Error communicating with Kafka: code=_MSG_TIMED_OUT Local: Message timed out

I upgraded my hop-client to the latest version on pypi hop version 0.6.0

[KaraMelih]

Also, my collagues started getting same / similar errors today

[KaraMelih]

Here is my colleague's error SNEWS2/SNEWS_Publishing_Tools#48 (comment)