I have a simple query loop that gets a MongoCursorNotFoundException after processing about 44,000 of 96,945 documents in around 93 minutes.
MongoIterable<MasterDocument> query = masterCollection.find().noCursorTimeout(true);
for (MasterDocument masterDocument : query) { ... do some stuff ... }
The "do some stuff" part takes a while, which is why the entire loop takes so long.
My problem is that I get this exception after handling maybe half of the documents in the collection.
I am running both the client application and the mongod server locally on my Windows 10 laptop, accessing the server via localhost.
The server log shows lots of messages like this:
{"t":{"$date":"2021-01-04T20:21:35.510-08:00"},"s":"I", "c":"COMMAND", "id":51803, "ctx":"conn27","msg":"Slow query","attr":{"type":"command","ns":"master_database.MasterCollection","command":{"find":"MasterCollection","filter":{"hashCode":1753339282},"$db":"master_database","lsid":{"id":{"$uuid":"6a252f51-2c6e-4c01-ae03-1a80aab109e0"}}},"planSummary":"COLLSCAN","keysExamined":0,"docsExamined":96944,"cursorExhausted":true,"numYields":96,"nreturned":0,"queryHash":"DBC59907","planCacheKey":"DBC59907","reslen":121,"locks":{"ReplicationStateTransition":{"acquireCount":{"w":97}},"Global":{"acquireCount":{"r":97}},"Database":{"acquireCount":{"r":97}},"Collection":{"acquireCount":{"r":97}},"Mutex":{"acquireCount":{"r":1}}},"storage":{},"protocol":"op_msg","durationMillis":147}}
The last of these messages is followed by:
{"t":{"$date":"2021-01-04T20:21:35.521-08:00"},"s":"I", "c":"NETWORK", "id":22944, "ctx":"conn27","msg":"Connection ended","attr":{"remote":"127.0.0.1:58990","connectionId":27,"connectionCount":14}}
{"t":{"$date":"2021-01-04T20:21:35.522-08:00"},"s":"I", "c":"NETWORK", "id":22944, "ctx":"conn26","msg":"Connection ended","attr":{"remote":"127.0.0.1:58989","connectionId":26,"connectionCount":13}}
{"t":{"$date":"2021-01-04T20:21:35.922-08:00"},"s":"I", "c":"-", "id":20883, "ctx":"conn25","msg":"Interrupted operation as its client disconnected","attr":{"opId":310196}}
I have tried:
Using "noCursorTimeout(true)" on the query cursor (as shown above)
Starting the server with "mongod --setParameter localLogicalSessionTimeoutMinutes=240". This last seems to have caused additional log messages that say "error":"Location13111: wrong type for field (expireAfterSeconds) long != int"
I am using mongod 4.4 and the latest mongo java api.
You may need to increase the default cursor idle timeout to bigger value in all shards and mongos:
check the parameter(default is 10 min = 600000 ms ):
use admin
db.runCommand({getParameter:1, cursorTimeoutMillis: 1})
and update to bigger value:
use admin
db.runCommand({setParameter:1, cursorTimeoutMillis: 600000000 })
also the COLSCAN in your logs indicate that you dont use indexes in your query , maybe you need to create one on "hashCode" ...
Thanks for the response.
It turned out that my application ran to completion once I started mongod with "--setParameter localLogicalSessionTimeoutMinutes=240, despite the error message that I saw in the console log.
You are absolutely right that I should have an index on "hashCode". (I had one before but forgot to recreate it after recreating the collection.)
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 recently started working with Robot framework. So I had a requirement where I needed to connect with Postgres db.
So though I am able to connect with the db but then when I try to execute queries, the flow is getting stuck. Even the test is not failing. Following is what I did:
Connect To Database psycopg2 ${DBName} ${DBUser} ${DBPass} ${DBHost} ${DBPort}
${current_row_count} = Row Count Select * from xyz
The first statement is executing fine but then it gets stuck on second statement.
Can somebody help me out on this
To Execute Query and get data from result :
Connect To Database psycopg2 ${DBName} ${DBUser} ${DBPass} ${DBHost} ${DBPort}
${output} = Query SELECT * from xyz;
Log ${output}
${DataResults}= Get from list ${output} 0
${DataResults}= Convert to list ${DataResults}
${DataResults}= Get from list ${DataResults} 0
${DataResults} convert to string ${DataResults}
Disconnect From Database
You are not executing your query.... read below a bit documentation and an example ;)
In the example you can see example variable but introduce your data ;)
Name: Connect To Database Using Custom Params
Source: DatabaseLibrary
Arguments:
[ dbapiModuleName=None | db_connect_string= ]
Loads the DB API 2.0 module given dbapiModuleName then uses it to connect to the database using the map string db_custom_param_string.
Example usage Example usage: :
Connect To Database Using Custom Params pymssql database='${db_database}' , user='${db_user}', password='${db_password}', host='${db_host}'
${queryResults} Query ${query}
Disconnect From Database
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).
I have an instance of Mongo running and can connect and authenticate successfully to a database. I can bulk insert records using collection.insert([list of records to insert]).
However, when I add safe=True to ensure that the records are inserted, like the following command, I get the error below, which seems like a permissions issue. How can I fix this?
collection.insert(records_to_insert, safe=True)
File "/.../python2.6/site-packages/pymongo/collection.py", line 270, in insert
check_keys, safe, kwargs), safe)
File "/.../python2.6/site-packages/pymongo/connection.py", line 732, in _send_message
return self.__check_response_to_last_error(response)
File "/.../lib/python2.6/site-packages/pymongo/connection.py", line 684, in __check_response_to_last_error
raise OperationFailure(error["err"])
pymongo.errors.OperationFailure: unauthorized
You are running in MongoDB in auth mode and did not provide the related the related credentials upon connection time. Calling db.authenticate(...) should be your friend.