MongoDb - find what is my current read and write concern for the cluster - mongodb

I am working with MongoDb version 4.2.
I searched the documentation to find how to get my cluster read and write concern defaults, but couldn't.
Is there no shell command that shows this?
Thanks

The getDefaultRWConcern administrative command retrieves the global default read or write concern settings.

Related

Not able to migrate the data from Parse to local machine

as some of you might aware about the shutting down of parse service in about a year, i am following the migration process as per their tutorials. However, i am not able to migrate these data from parse to local database(i.e. mongodb).
I've started the mongodb instanse locally on 27017, and also created an admin user as part of migration based on these tutorials. Reference-1 & Reference-2.
But when i try to migrate the data from parse developer console, i get No Reachable Servers or Network Error & i don't understand why. I have doubt in the Connection string that i use for this but i am not sure, please find the following image.
I am new to mongodb so don't have much idea about this, your little help would be greatly appreciated.
Since the migration tool runs at parse.com, the tool needs to be able to access your MongoDB instance over the Internet.
Since you're using a local IP (192.168.1.101), parse.com cannot connect to your IP and the transfer will time out.
Either you need to make your MongoDB reachable from the Internet, or you can - as they do in their guide - use an existing MongoDB service.

MongoDB replica set in Azure "Waiting for role to start... Calling OnRoleStart()"

I have a problem trying to implement a mongodb replica set as a worker role instance in Windows Azure. In the Windows Azure portal, one of the instances is shown as busy with the status:
Waiting for role to start... Calling OnRoleStart()
I have checked all the settings and everything seems to be ok, what could the problem be?
Denis Markelov's blog post helped me solve this problem. The solution is mainly his, however I had to take an extra step to get it to work and thought others might find it useful.
Solution from blog:
Windows Azure reuses virtual machines for roles, so after a fresh
deployment on a hard drive you can find files that were created during
previous sessions. If MongoDB was terminated improperly - there might
be a lock file ("persisted mutex" analogue), because of which MongoDB
refuses to start. It is located at the drive with a label
"WindowsAzureDrive" (say it is F:), at the path:
F:\data\mongod.lock
In the case of a production use this situation might require a
recovery procedures, but if you are just in the process of initial
setup - it is safe to remove this file, letting MongoDB to start
again.
I was having this problem and did as suggested, however I was still having the same problem. So I took a look at the log file at
C:\Resources\Directory\.MongoDB.WindowsAzure.MongoDBRole.MongodLogDir\mongod.txt
And saw that another file was also giving an error. In order to fix the problem, you also have to delete the file local.ns in the same directory as mongod.lock.

How to get PostgreSQl log

How can I get log information from PostgreSQl server?
I found ability to watch it in pgAdmin Tolls->ServerStatus. Is there a SQL way, or API, or consol way, to show content of log file(s)?
Thanks.
I am command line addict, so I prefer “console” way.
Where you find logs and what will be inside those depends on how you've configured your PostgreSQL cluster. This the first thing I change after creating a new cluster, so that I get all the information I need and in the expected location.
Please, review your $PGDATA/postgresql.conf file for your current settings and adjust them in the appropriate way.
The adminpack extension is the one providing the useful info behind pgAdmin3's server status functionality.

OpenLdap redirect on write

I am currently trying to setup a redirect on write for an installation of OpenLdap 2.2.
I have two instances running. One is configured to be read-only (only read access, database specified as read-only) and has redirect configured to point to the second instance. The second instance is configured to allow for the desired write permissions.
When I attempt a modify on the first instance it fails as expected but does not send back the referral. Am I missing a piece of the configuration? Am I even on the right path? Any guidance would be greatly appreciated. Thanks.
In the database section of you slapd.conf do you add the redirection like this ? :
updateref "ldap://master-host:port/"
So, it turns out the best way to do this is to go ahead and set up replication using slurpd and point all requests at the slave instance. Unfortunately you can't set up the master and slave on the same host (for obvious reasons, but still), so I had to spin up a second VM to get this going.
Honestly, if I was not trying to replicate a redirect problem it wouldn't be worth it, but I have to duplicate a production issue.
For more information on slapd and specifically slurpd, the OpenLDAP documentation is actually crazy helpful: slurpd config for OpenLDAP 2.2

DB2 Transaction log is full. How to flush / clear it?

I’m working on a experiment regarding to a course I’m taking about tuning DB2. I’m using the EC2 from Amazon (aws) to conduct the experiment.
My problem is, however, that I have to test a non-compression against row-compression in DB2 and to do that I’ve created a bsh file that run those experiments. But when I reach to my compression part I get the error ”Transaction log is full”; and no matter how low I set the inserts for it is complaining about my transaction log.
I’ve scouted Google for a day now trying to find some way to flush / clear the log or just get rit of it, i don’t need it. I’ve tried to increase the size but nothing has helped.
Please, I hope someone has an answer to solve this frustrating problem
Thanks
- Mestika
There is no need to "clear the log" in DB2. When a transaction is rolled back, DB2 releases the log space used by the transaction.
If you've increased the log size and it has not helped, please post more information about what you're trying to do.
No need of restarting. Just try to force the applications using DB2 force applications all.
Increase the Actie Log File Size and try to force application connections and terminate the connections.
Try to run the job now.
db2 force applications all
db2 update db cfg for sample using logfilsiz 5125
db2 force applications all
db2 terminate
db2 connect to sample
Run your job and monitor.
Just restart the instance, it would release the pending logs and you should be fine