I'm working on upgrading to the new transaction API. In my existing app and have this pattern for transaction management: ```
begin
tx = Neo4j::Transaction.new(ActiveGraph::Base.current_session)
# business logic hererescue StandardError => e
add_error(:new_object, :save, "Final save transaction was a failure: #{e}")
tx.failure
ensure
tx.close
end
```
What is the equivalent using the activegraph v10/11 api?
44 replies
We're using neo4j 3.5 (hosted version Aura). We're using
gem 'activegraph', '10.0.2'
gem 'neo4j-ruby-driver', '1.7.5'
Pretty frequently we get these exceptions. At times they bring the application down (no request works), other times they are intermittent.09 Apr 2021 21:07:53.2812021-04-09 21:07:53 +0000 severity=ERROR, #<Neo4j::Driver::Exceptions::SessionExpiredException: code: `fff`, error: `4`, state: `4`, error_context: `secure_openssl_send(/tmp/seabolt/src/seabolt/src/bolt/communication-secure-openssl.c:469), SSL_write error code: 5, underlying error code: 32`>
DEPRECATION WARNING: The ActiveGraph::Relationship::Query module has been deprecated and will be removed in a future version of the gem. (called from rescue in irb_binding at (irb):53)
CYPHER
MATCH (n1:
ServiceMonitor)-[r1:UPSTREAM_OF]->(n2:ServiceMonitor)WHERE (r1.service_group = 'telo_logging')
RETURN r1
BOLT: 0ms
CYPHER
MATCH (n)
WHERE (ID(n) = $ID_n)
RETURN n | {:ID_n=>63}
BOLT: 0ms
Traceback (most recent call last):
2: from (irb):52
1: from (irb):53:in `rescue in irb_binding'
TypeError (no implicit conversion of Integer into String)
2 replies
In this repo directory I put the results of my first run at getting those instructions to work. The fix described is because of ruby 3.0.0.
https://github.com/oaklodge/activegraph/tree/master/fixit
But I'm testing an instance of Aura 4.2 and it seems I'm able to connect and queries using neo4j:// and encryption true. Am I missing something? What should I expect using activegraph 10.1.0 and Neo4j 4.2?
Thank you in advance.
3 replies
Hello @klobuczek, I have question. We implementing in project connection to Neo4j cluster by neo4j:// protocol. We are using neo4j-java-driver in version 4.2.0. Unfortunately when we trying to connect to neo4j and list databases like here:
ActiveGraph::Base.driver.session_orig.run("SHOW DATABASE $db_name", db_name: db_name)We see error message:
Unable to authenticate request (Neo4j::Driver::Exceptions::SessionExpiredException): Server at IP_ADDRESS:7687 no longer accepts writesDo you have some idea what we doing wrong?
session_orig because that’s not a driver nor activegraph method, but in general the “… no longer accepts writes” error is usually due to the selected server not being a leader at the transaction commit (it might have been at the time it was selected). If you are getting a lot of those errors then the servers might be switching leader very often. This could be related to how your cluster is setup and configured in relation to available resources. Check the logs if the leader switches are actually happening.
You're right @klobuczek. I've forgot to mention about session_orig. But anyway even if I use
ActiveGraph::Base.driver.session(Neo4j::Driver::AccessMode::READ).run("SHOW DATABASE $db_name", db_name: db_name)I see the same error, what is quite strange cause I'm using READ access mode. I'm using it wrongly?
def session(**session_config)
@klobuczek I've changed my code a bit and useed write_transaction and read_transaction methods.
Now I'm doing something like this
ActiveGraph::Base.write_transaction do |tx|
tx.run("CREATE DATABASE $db_name IF NOT EXISTS", db_name: db_name).to_a
endSo generally it should be fine, but there similar error:
WARNING: Transaction failed and will be retried in 13462ms
2021-05-26T10:44:15.991+02:00 org.neo4j.driver.exceptions.SessionExpiredException: Server at 10.13.201.236:7687 no longer accepts writesSo mine question is - method write_transaction should automatically connect to leader or we have to somehow show which one node is a leader?
Another thing is that my colleague find information that when we working on administrative things like creating db or showing db we should use system db to connect. Do you have idea how to force using system db?
Now I created the database and want to perform operation on this database
ActiveGraph::Base.session(database: "new_db") do |tx|
tx.run("CALL apoc.import.graphml(\"#{dump_url}\", {batchSize: 20000, readLabels: true})").to_a
endbut I get error from neo4j:
Unable to authenticate request (Neo4j::Driver::Exceptions::SessionExpiredException): Failed to obtain connection towards WRITE server. Known routing table is: Ttl 1622027172140, currentTime 1622026872142, routers AddressSet=[IP1:7687, IP2:7687, IP3:7687], writers AddressSet=[], readers AddressSet=[IP1:7687], database 'new_db'Should I somehow reload routing table or just make connection differently?
WARNING: Transaction failed and will be retried in 13462ms
write server is currently not capable to do writes. There is automatic retry in the driver which will execute the entire transcation again with a newly selected server until successfull or some configurable time threshold is exceeded.
run method as well. However that method is not retryable so you get an error on first attempt.
neo4j-ruby-driver and plan on upgrading to activegraph from neo4j.rb. I'm having difficulty finding seabolt drivers above 1.7.5. Is our only option to use neo4j-java-driver and run our app on JRuby?