I want to connect my local Nodejs (NO JVM) application using Gremlin/Tinkerpop to a remote OrientDB 3.x instance. Is that possible at all? How?
I tried it using "gremlin" npm library without success.
const gremlin = require('gremlin');
const DriverRemoteConnection = gremlin.driver.DriverRemoteConnection;
const traversal = gremlin.process.traversal;
const PlainTextSaslAuthenticator = gremlin.driver.auth.PlainTextSaslAuthenticator;
const authenticator = new PlainTextSaslAuthenticator('root', 'admin');
const g = await traversal().withRemote(new DriverRemoteConnection('wss://localhost:8182/demodb', {authenticator: authenticator}));
And would expect it to connect, but instead I get this error:
Unhandled exception at: Error: Client network socket disconnected before secure TLS connection was established
at TLSSocket.onConnectEnd (_tls_wrap.js:1177:19)
at Object.onceWrapper (events.js:285:13)
at TLSSocket.emit (events.js:202:15)
at endReadableNT (_stream_readable.js:1129:12)
at processTicksAndRejections (internal/process/next_tick.js:76:17)
Ok I managed to do it with url ws://localhost:8182/gremlin, and the database accessed by gremlin I configure in the gremlin-server.yaml file in the OrientDB folder.
Related
From the typeorm docs:
Generally, you call initialize method of the DataSource instance on application bootstrap, and destroy it after you completely finished working with the database. In practice, if you are building a backend for your site and your backend server always stays running - you never destroy a DataSource.
But, for implementing postgres's schema based multitenancy, I'm scoping connections per request, because, each request has to be sent to a different schema. So, in my getConnection option, I'm doing this:
async function getTenantConnection(
tenantName: string,
connectionOptions?: PostgresConnectionOptions,
) {
if (!connectionOptions) {
connectionOptions = baseConnection;
}
const options: PostgresConnectionOptions = {
...connectionOptions,
schema: tenantName,
entities: [__dirname + '/../**/*.entity.js'],
synchronize: false,
};
const dataSource = new DataSource(options);
return await dataSource.initialize();
}
so on each request, I'm doing getTenantConnection which sort of initialized the database. The previously available getConnection() seems deprecated, and now doing stress tests on the app, I'm getting TCP connection issues, which I simply cannot debug:
5;3m[ExceptionsHandler] connect ETIMEDOUT 20.119.245.111:5432
2023-01-31T10:40:40.581303183Z Error: connect ETIMEDOUT 20.119.245.111:5432
2023-01-31T10:40:40.581370686Z at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1278:16)
2023-01-31T10:40:40.581381886Z at TCPConnectWrap.callbackTrampoline (node:internal/async_hooks:130:17)
2023-01-31T10:40:40.589395960Z [Nest] 53 - 01/31/2023, 10:40:40 AM ERROR [ExceptionsHandler] connect ETIMEDOUT 20.119.245.111:5432
I'm just speculating that the database pool has something to do with this. I don't understand the code fully, but the source code for typeorm doesn't seem to contain any pooling done in the initialize() method section as well. I had tried to take reference from this article which demonstrates schema based multitenancy in postgres using typeorm , but methods available there aren't available anymore so I had to resolve to using .initialize(). Please let me know how I can go about implementing this.
When I install strapi via npm, then run "strapi new server" and then try to connect to mongodb atlas; It shows the following error.
(node:12564) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.
⛔️ Connection test failed: failed to connect to server [oriapp-shard-00-01.pjvsw.mongodb.net:27017] on first connect [MongoNetworkError: connection 5 to oriapp-shard-00-01.pjvsw.mongodb.net:27017 closed
at TLSSocket. (C:\Users\Sharm\AppData\Local\Temp\strapi236c8a243294\node_modules\strapi-connector-mongoose\node_modules\mongodb\lib\core\connection\connection.js:356:9)
at Object.onceWrapper (events.js:422:26)
at TLSSocket.emit (events.js:315:20)
at TLSSocket.EventEmitter.emit (domain.js:483:12)
at net.js:674:12
at TCP.done (_tls_wrap.js:567:7) {
[Symbol(mongoErrorContextSymbol)]: {}
}]
So , the solution to the above problem:
Reinstall strapi using npm or yarn or any other package manager.
The ip whitelist in mongodb atlas in your cluster should have the ip address of your system.
when aysnchronous function is defined use Ipv4 in place of "localhost:1337".
Thus one will be good to go.
We have IBM Cloud PostgreSQL instance. We are connecting to it using node-postgres client or odbc client with Data Direct Driver. As per our understanding the PostgreSQL service instance should throw error when provide incorrect host while connecting. However, the instance is not throwing any error when providing incorrect host (incorrect value for the first part of the host string before dot operator).
Steps to reproduce the issue
Create IBM Cloud PostgreSQL instance. Below is the format of host string
<<1st part of host>>.<<2nd part of host>>.databases.appdomain.cloud
Connect to instance using node client using node-postgres client or odbc client with Data Direct Driver with incorrect value for the first portion(<<1st part of host>>) of the host.
It will connect successfully without any issue. If we provide incorrect value(<<2nd part of host>>.databases.appdomain.cloud) for remaining portion it throws error.
Used below code snippet for validating this scenario:
const pg = require('pg')
const connectionString = 'postgres://user:password#<<1st part of host>>.<<2nd part of host>>.databases.appdomain.cloud:31974/ibmclouddb?sslmode=verify-full'
const caCert = 'Self Signed CA Certificate'
const client = new pg.Client(
{
connectionString: connectionString,
ssl: {
ca: caCert,
rejectUnauthorized: false
}
}
)
client.connect()
client.query('select * from test_pg.char_test4').then(res => {
console.log('res.rows :::::: ', res)
}).finally(() => client.end())
I am developing a C# MVC Web API which uses MongoDb as backend.I tried connecting to my mongodb database using
MongoClient mongoClient = new MongoClient(connectionString)
where connectionstring is in format : mongodb://Username:Password#hostname.eastus.cloudapp.azure.com
Mongo db is hosted in a virtual machine in Azure.I am able to connect to the database and all works good.But I am getting frequent exceptions:
"MongoDb.driver.MongoConnectionException".An exception occurred while
receivinf a message from server--->System.IO.IOException:Unable to
read data from the transport connection : A connection attempt failed
because the connected party did not properly respond after a period of
time,......"
So after a bit of research I have learnt that Azure is killing idle connections and I have to set MaxConnectionIdleTime.
In order to set MaxConnectionIdleTime I decided to connect to Mongodb in the below way
var credential = MongoCredential.CreateCredential("dbname", "UserName", "Password");
var settings = new MongoClientSettings
{
Credentials = new[] { credential },
Server = new MongoServerAddress("HostName", 27017),
MaxConnectionIdleTime = new TimeSpan(0, 3, 0)
};
MongoClient mongoClient = new MongoClient(settings);
In this case I am using the same username,password combination given in the connection string which I used to connect before.
While trying to connect here I am getting inner Exception:
MongoDB.Driver.MongoAuthenticationException: "Unable to authenticate
using sasl protocol mechanism SCRAM-SHA-1".
"MongoDb.driver.MongoConnectionException".An exception occurred while receivinf a message from server--->System.IO.IOException:Unable to read data from the transport connection : A connection attempt failed because the connected party did not properly respond after a period of time,....
The reason behind this exception is when hosted in Azure,Azure tries to kill the idle connections but the C# driver is not aware of this.The driver tries to execute queries on the killed connections without knowing the connection is not existing.
The solution that worked out for me is to set maxIdleTimeMS=45000 in connection string.
This way driver will not use a connection which has been idle for long time.
Here is the connection string that worked out for me
connectionString="Username:Password#hostname.eastus.cloudapp.azure.com/?connectTimeoutMS=30000&socketTimeoutMS=30000&waitQueueTimeoutMS=30000&maxIdleTimeMS=45000"
I have had a similar error with my Azure hosted MongoDb (Cosmos Db). It turned out to be network settings such that I had blocked all access. Changing it to Allow access from "All networks" fixed the issue.
The error is very misleading, I would have expected a connection timeout.
A timeout occured after 30000ms selecting a server using
CompositeServerSelector{ Selectors =
MongoDB.Driver.MongoClient+AreSessionsSupportedServerSelector,
LatencyLimitingServerSelector{ AllowedLatencyRange = 00:00:00.0150000
} }. Client view of cluster state is { ClusterId : "1", ConnectionMode
: "ReplicaSet", Type : "ReplicaSet", State : "Disconnected", Servers :
[{ ServerId: "{ ClusterId : 1, EndPoint :
"Unspecified/XXXX.documents.azure.com:10255" }", EndPoint:
"Unspecified/XXXX.documents.azure.com:10255", State: "Disconnected",
Type: "Unknown", HeartbeatException:
"MongoDB.Driver.MongoConnectionException: An exception occurred while
opening a connection to the server. --->
MongoDB.Driver.MongoAuthenticationException: Unable to authenticate
using sasl protocol mechanism SCRAM-SHA-1. --->
MongoDB.Driver.MongoCommandException: Command saslContinue failed: Not
Authenticated.
To troubleshot I tried from MongoDb Compass as well and that didn't work either, showing me it wasn't the code.
I've come across a node chat example on github, When I try to run it, I see the following error:
Error connecting to mongo perhaps it isn't running ?
I've installed mongo 0.9.2, nodejs 5.2 pre, npm 3.0 and other dependencies. The example can be found here: https://github.com/gregstewart/chat.io
I can not determine whether if the example not really works or I didn't run it right. Please help.
Did you install and start mongo-db on your system? This error is mostly because of a missing mongo instance running on the local machine.
Check out the follwing code excerpts from chat.io.
main.js:
/**
* Configure the user provider (mongodB connection for user data storage)
*/
var userProvider = new UserProvider('localhost', 27017);
Creates a new UserProvider object using host and port for database (localhost:27017, mongo-db default).
UserProvider.js:
UserProvider = function(host, port) {
this.db = new mongo.Db('node-mongo-chat', new Server(host, port, {auto_reconnect: true}, {}));
this.db.addListener('error', function(error) {
console.log('Error connecting to mongo -- perhaps it isn\'t running?');
});
this.db.open(function() {
});
};
Opening the connection to the server, printing out an error on failure (the error you mentioned above).
Consider reading up on the mongo-db docs concerning installation and setup here