Using mongodb erlang driver my program able to connect mongodb database server.
After successful connection I tried to all the documents present in the collection.
I tried the below code:
mongo:do (safe, master, Conn, graph, fun() ->
process(mongo:find (pedgedata0, {src,1})) end),
here 'graph' is dbname and 'pedgedata0' is collection.
I tried with different options like
mongo:do (safe, master, Conn, 'graph', fun() ->
process(mongo:find ('pedgedata0', {})) end),
* here I tried with single quotes for db and collection name and also specified an empty condition.
However I am getting below error:
Conn is : <0.104.0>
** exception exit: undef
in function bson_binary:put_cstring/1
called as bson_binary:put_cstring(<<"graph.pedgedata0">>)
in call from mongo_protocol:put_message/3
in call from mongo_connection:encode_request/2
in call from mongo_connection:handle_call/3
in call from gen_server:handle_msg/5
in call from proc_lib:init_p_do_apply/3
I am running this program from erlide(Eclipse addon for erlang).
Please help me to resolve this problem
Please use the newer version of driver: https://github.com/comtihon/mongodb-erlang
There are renewed interfaces for mongo operations.
Related
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.
1. {ok,P}= mongoc:connect({rs, <<"dev_mongodb">>, [ "dev_mongodb001:27017", "dev_mongodb002:27017"]}, [{name, mongopool}, {register, mongotopology}, { rp_mode, primary},{ rp_tags, [{tag,1}]}], [{login, <<"root">>}, {password, <<"mongoadmin">>}, {database, <<"admin">>}]).
2. {ok, Pool} = mc_topology:get_pool(P, []).
3. mongoc:find(Pool, {<<"DoctorLBS">>, <<"mongoMessage">>}, #{<<"type">> => <<"5">>}).
I used latest version in github, and got an error at step 3.
It seems my selector is not valid, is there any example of how to use mongodb-erlang ?
My mongodb version is 3.2.6, auth type is SCRAM-SHA1.
mongoc:find(Pool, <<"mongoMessage">>, #{<<"type">> => <<"5">>}).
I tried this in rs and single mode, still got this error.
Is there any other simple way to connect and read?
I just need to read some data once from mongo when my erlang program start, no other actions.
Todays version of mongo does not support tuple colldb due to new query api introduced in mongo 2.6
You should connect to DoctorLBS database instead, and than use
mongoc:find(Pool, <<"mongoMessage">>, #{<<"type">> => <<"5">>}).
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
Im running a workflow in powercenter that is constatnly getting an SQL1224N error.
This process execute a query against one table (POLIZA) with 800k rows, it retrieves the first 10k rows and then it start to execute to another table with 75M rows, at ths moment in DB2 an idle thread error appear but the PWC process still running retrieving the 75M rows, when it is completed (after 20 minutes) the errros comes up related with the first table:
[IBM][CLI Driver] SQL1224N A database agent could not be started to service a request, or was terminated as a result of a database system shutdown or a force command. SQLSTATE=55032
sqlstate = 40003
[IBM][CLI Driver] SQL1224N A database agent could not be started to service a request, or was terminated as a result of a database system shutdown or a force command. SQLSTATE=55032
sqlstate = 40003
Database driver error...
Function Name : Fetch
SQL Stmt : SELECT POLIZA.BSPOL_BSCODCIA, POLIZA.BSPOL_BSRAMOCO
FROM POLIZA
WHERE
EXA01.POLIZA.BSPOL_IDEMPR='0015' for read only with ur
Native error code = -1224
DB2 Fatal Error].
I have a similar process runing against the same 2 tables and it is woking fine where the only difference I can see is that the DB2 user is different.
Any idea how can i fix this?
Regards
The common causes for -1224 are:
Your instance or database has crashed, or
Something/somebody is forcing off your application (FORCE APPLICATION or equivalent)
As for the crash, I think you would know by know. This typically requires a database or instance restart. At any rate, can you please have a look into your DIAGPATH to check for any FODC* directories whose timestamp would match the timestamp of the -1224 errors?
As for the FORCE case, you should find some evidence of the -1224 in db2diag.log. Try searching for the decimal -1224, but also for its hex representation (0xFFFFFB38).
the following code leaves an empty dummy database. Is this system behavior intended?
mongodb is running --auth mode and the user is part of the readAnyDatabase Role.
import pymongo
print CORE_PROD_URL
mongo = pymongo.MongoClient(CORE_PROD_URL)
print mongo.database_names()
print mongo.dummy.test.count()
print mongo.database_names()
which gives:
mongodb://read_only_user:pw#localhost:27017
[u'admin', u'local']
0
[u'admin', u'local', u'dummy']
the same behaviour happens with find()
while
mongo.dummy.test.insert({‘foo’: ‘bar’})
throws an exception
OperationFailure: not authorized on new_db to execute command
This is a known bug, SERVER-11051. The database name will disappear from "database_names()" the next time you restart the server, but of course it will reappear next time you read from the "dummy" database.