Apache AGE - Server terminated abnormally on missing arguments of cypher function

Question

I ran a query on my graph using the following code:

SELECT * FROM cypher('demo_graph') as (v agtype);

However, I forgot to include the query argument for the Cypher function. As a result, the server closed the connection unexpectedly, and I received the error message

server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.
The connection to the server was lost. Attempting reset: Failed.

I was expecting an exception to be raised instead of the server being terminated.

Yes, I have also encountered the same error, multiple times, and in the end, it automatically reconnects to the server and works normally. I recommend You to open an issue regarding this error at https://github.com/apache/age/issues In this case, as the server crashes this transaction is rolled back, and previous changes are committed. So such queries do not affect your database, and your server starts again, safely. — Kamlesh Kumar, Feb 24 '23 at 16:40

score 0 · Answer 1 · answered Feb 24 '23 at 20:44

0

You are missing the cypher query:

SELECT * FROM cypher('demo_graph', $$ your cypher query goes here $$) as (v agtype);

answered Feb 24 '23 at 20:44

Rafsun Masud

89
2

Yes, they said so in the question. **That was the point**. The question is *why does the server then disconnect*? – Martijn Pieters Mar 15 '23 at 19:01

Hammad Saleem · Answer 2 · 2023-04-15T10:33:14.260

0

I think the server is terminating and this is happening because of an empty query. To Resolve this issue try using the below code and run

query = "MATCH (n) RETURN n LIMIT 9"
if query.strip() == "":
    raise ValueError("String query empty ")
res = conn.execute(f"SELECT * FROM cypher('my_graph', '{query}') as (v agtype)")

edited Apr 15 '23 at 10:33

answered Apr 15 '23 at 09:59

Hammad Saleem

375
8

score 0 · Answer 3 · answered Jun 30 '23 at 11:29

The error message you received is correct. The cypher function in Apache AGE expects a query argument. If you do not provide a query argument, the server will terminate abnormally.

The reason for this is that the cypher function is a remote procedure call (RPC). RPCs are a way of calling a function on a remote server. When you call the cypher function, the server starts a new thread to execute the query. If you do not provide a query argument, the server has no way of knowing what query to execute, so it terminates abnormally.

You can avoid this error by providing a query argument to the cypher function.

This is was a bug on AGE. You can refer to this [issue](https://github.com/apache/age/issues/718) on AGE's repo. It's fixed now. — Abdul Manan, Jun 30 '23 at 15:06

score 0 · Answer 4 · answered Jul 12 '23 at 09:21

0

Server is terminating abnormally because a cypher query is missing. Use the below query argument to avoid the error:

SELECT * FROM cypher('demo_graph', 
$$ write your cypher query $$)
as (v agtype);

answered Jul 12 '23 at 09:21

Aadil Bashir

111
5

score 0 · Answer 5 · edited Aug 13 '23 at 07:23

0

The reason behind the termination of server is missing cypher query. So you need you update your query

SELECT * FROM cypher('demo_graph', $$MATCH (n) RETURN n$$) AS (v agtype);

edited Aug 13 '23 at 07:23

Mohayu Din

433
9

answered Jul 24 '23 at 21:44

adil shahid

125
4

score 0 · Answer 6 · answered Aug 12 '23 at 23:42

0

The bug was fixed in this commit by adding a check for the number of arguments to be exactly two.

answered Aug 12 '23 at 23:42

Mohayu Din

433
9

score 0 · Answer 7 · answered Aug 22 '23 at 12:21

Your incomplete query requires cypher query to be completed.

Sample Syntax of query:

SELECT * FROM cypher('demo_graph', $$
        //Desired Operations
    $$) AS (n agtype);

Example:

SELECT * FROM cypher('demo_graph', $$
    MATCH (n:Person)
    WHERE n.age > 30
    RETURN n
$$) AS (n agtype);

Apache AGE - Server terminated abnormally on missing arguments of cypher function

7 Answers7