I have a working script, and in my node code, I have instances of save(), like the following:
user.remove(function(error, removedMeasurement) {
if (error) {...} else {...}
});
I would like to confirm that something is done when handling an error during the save(). I tried killing my connection to the db after I started the process, but then the process just hangs without error.
My connection to the db is similar to
db = mongoose.createConnection(connectionToDb, options);
and the options include:
reconnectTries:60,
reconnectInterval:2000
If I restart the db connection right away, the script will continue, so I think the above attribute options have something to do with this, and so killing the db connection does not help trigger the error to confirm I am handling it correctly.
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.
I'm currently working on a simple python CRUD script to check MongoDB out. Turns out I'm liking it a lot, but I have found myself being unable to work with MongoDB transactions. Everytime I try to start a transaction an exception is thrown saying:
This MongoDB deployment does not support retryable writes. Please add retryWrites=false to your connection string.
And, eventhough I've already added that option to my connection string:
self._client = MongoClient('mongodb://localhost/?retryWrites=false')
self._db = self._client.workouts
self._collection = self._db.workouts
That error is still popping up when running the following lines of code:
with self._client.start_session() as s:
with s.start_transaction():
self._collection.delete_one({'_id': id}, session=s)
next = self._collection.find_one({'_id': next_id}, session=s)
return next
What can I do?
I'm running python 3.7.3, pymongo 3.9.0 and MongoDB 4.0.12.
I'm trying to create an alarm system for my application, that will trigger when one of the services (e.g. MongoDB) is not working.
What I'm doing is, once the application is started, I shut down my MongoDB server and try to connect to it, but instead of receiving an error my application just gets stuck into the execution of the method. The server console looks like something is in execution.
My current code (coffeescript) is:
checkMongoService: ()->
mongo = Npm.require 'mongodb'
assert = Npm.require 'assert'
url = 'mongodb://....'
mongo.connect url, (err, db) ->
assert.equal null, err
console.log 'Connected correctly to server'
db.close()
return
I've also been trying by doing a simple
Meteor.users.find().count();
or using MongoInternals with
testConnection = new MongoInternals.RemoteCollectionDriver("mongodb://...);
but still same issue, when mongo is not running no error is thrown and the console stops to work. If then I start Mongo again, it will just return the result (in this case the log 'Connected correctly to server')
Something that I've noticed is if I try with meteor shell to execute testConnection = new MongoInternals.RemoteCollectionDriver("mongodb://...); I get an error "Error: failed to connect to [127.0.0.1:27017]"
TL;DR
Do you might have an idea on how I can check if mongo is reachable or do you know if I'm doing something wrong with the code above?
Try setting the timeouts to be a bit shorter than the default 30 seconds:
mongo.connect(url, {
connectTimeoutMS: 1000,
socketTimeoutMS: 1000,
reconnectTries: 1
}, function(err, db) {...}
(Full set of connection params are here)
Meteor.status().status
from the docs
This method returns the status of the connection between the client and the server. The return value is an object with the following fields:
connected (Boolean)
True if currently connected to the server. If false, changes and method invocations will be queued up until the connection is reestablished.
status (String)
Blockquote
Describes the current reconnection status. The possible values are connected (the connection is up and running), connecting (disconnected and trying to open a new connection), failed (permanently failed to connect; e.g., the client and server support different versions of DDP), waiting (failed to connect and waiting to try to reconnect) and offline (user has disconnected the connection).
https://docs.meteor.com/api/connections.html
I am currently experiencing a SQL Timeout when running a SQL() command inside of an EF Migration.
Situation:
I am replacing a bunch (>50) tables with one table, and need to convert the data from those tables I'm about to drop into the new table. I've organized the Migration the following way:
1.Create the new table.
In the same Migration, use the SQL() function to run a sql script that migrates the data.
3.Drop all the old tables.
Currently, the migration gives the following error:
System.Data.SqlClient.SqlException (0x80131904): Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.
The statement has been terminated. ---> System.ComponentModel.Win32Exception (0x80004005): The wait operation timed out
The error is happening in an environment where I give them an installer, and they run it without me involved, so I can't manually run individual migrations, and pause in the middle to run the SQL script.
Is there any way to change the timeout for a connection, or get around this issue?
Environment:
EF 6.0 Code First
SQL Server 2012
See this answer.
Use Configuration.cs file to set custom time out:
internal sealed class Configuration :
DbMigrationsConfiguration<ApplicationDbContext>
{
public Configuration()
{
AutomaticMigrationsEnabled = false;
ContextKey = "YourDbContext";
// New timeout in seconds
this.CommandTimeout = 60 * 5;
}
}
With this method, you can change the timeout only for migration and not everyone using your default connection string.
You should be able to set the connection timeout in the connection string, something like:
Connection Timeout=180;
Quite simply, I'm trying to connect to a MongoDB via Node.js:
Db = require('../v2/node_modules/mongodb').Db
Connection = require('../v2/node_modules/mongodb').Connection
Server = require('../v2/node_modules/mongodb').Server
console.log "before"
DbServer = new Server("localhost", 27017, {})
db = new Db("twitter", DbServer, {native_parser:true})
console.log "after"
return
That's my code and it's as simple as it gets. My output, however, seems to stop at the db = new Db... line.
It never gets to the after. It doesn't give an error either. I know I have a DB running and when I fire up MongoHub, it's there along with the twitter database
Just remove the native_parser=true would be ok
Native bson parser not compiled, please compile or avoid using native_parser=true