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.
Related
I ran various containers on Two different Windows 10 Pro machines, and thought that I had the data drives mapped correctly, but now I'm finding out that it isn't writing the data there at all. One example was Mongo db, where I mapped /mongodb/database:/data/db I upgraded docker, and when it restarted mongodb.. POOF! no data, I thought that was weird and looked in /mongodb/database and the directory is empty. Thankfully, the app is still in the development phase, and not critical that the data was lost...
the line from the docker compose file:
volumes:
- /mongodb/database:/data/db
Different machine:
I installed Gogs/gogs image, mapping the data:
docker run --name=Gogs-Git -p 10022:22 -p 10080:3000 -v /var/gogs:/Docker/Gogs-GitServer/Data gogs/gogs
Seemed to work perfectly, so I was thinking everything was fine, I pushed a Repo up to it.. and today, I looked at \Docker\Gogs-gitserver\data and no files... so where did it write the data?
I also installed TeamCity, mapping that data.. nope, it has no logs, no data...
This feature seems to just not work at all. I found a reference from 2016 saying I need to look at the 'shared' tab (below general),and check C: to be shared, but well, no, that isn't a tab, so it isn't that.
There is no way someone would write a system that just quietly wrote the data some other place, or didn't bother actually mapping it without giving an error - that would be nuts.
So, there must be some other explanation... One of the machines has Hyper-V enabled in the BIOS, the other one doesn't even support it as far as I know.
I think some of the images are Linux, and some are Windows (TeamCity I'm pretty sure is)
OK, this is interesting... If I look at the volumes, and enter one that is in use, I get this:
The Target looks about like the right path, but I'm not sure about the /backup and the /data on the last two lines, if these are supposed to be directories under that, they don't exist, but if I click on the data tab, I can see the data, it is in Docker, hidden and not shared, in spite of there being a 'target' that points at the right directory... how to I get it to start writing this data correctly to that folder??
I've not confirmed this yet with the above configuration, but I found that for other containers, I needed to specify the path as 'c:/data/MongoDb/Database' when I created the container using that as the path, it worked and I have data there now. I just need to go back and fix all these VMs so they have their data correctly...
I have a cluster of machines hosting hadoop (MapR) and have install streamsets on one of the nodes (say node002) following the RPM documentation. However, I am accessing the web UI for the data collector from another node, node001.
My question is, when I specify files paths (eg. an origin directory), which file system is the web UI going to be referring to? Eg. if I put an origin directory as /home/myuser/mydata, will the pipeline created in the web UI be looking for that directory in node001 or node002? New to using streamsets, so a more detailed answer would be appreciated. Thanks.
** Ultimately I am asking this because I am currently getting "FileNotFound" and "permission denied" errors while trying to follow the documentation's tutorial and am trying to debug the situation.
From the streamsets community forums: It will be the path to the local file on the machine running that particular SDC instance.
The FileNotFound and permission errors have to do with the fact that the default user for the sdc service is a user called sdc. Still working on how to fix this part, but can produce a workable prototype by setting the read and write access for the directories in question to allow public access (still need to work on this part, but this answers the posted question).
I'm relatively new to chef and am in the process of using the edelight mongodb cookbook. I've got the process of actually creating a standalong mongodb instance working fine. It's understanding how to use the subsequent user_management recipe to create the initial admin user and regular users.
When I add "default['mongodb']['config']['auth'] = true" to the attributes/default.rb file, and run the mongodb::default recipe, the db is created and authentication is on.
However when I run the mongodb::user_management recipe I get this error every time. Clearly I'm doing something wrong, but being new to editing chef/ruby files I can't determine what's failing. Looks like I might need to work within the users.rb attribute file?
===================================================
Error executing action add on resource 'mongodb_user[admin]'
NameError
uninitialized constant Mongo::MongoClient
The edelight cookbook has been unmaintained for quite some time now. Chef-Brigade is attempting to take over maintenance on the cookbook until a new owner can be found.
https://github.com/chef-brigade/mongodb-cookbook
There is work being implemented to fix some of the user_management issues. I am not 100% sure the current state of the user_management fixes but you would likely be better off starting with that cookbook and reporting any issues to the team there so they can work to resolve. There is active development taking place.
I would be glad to help you debug the issue if it persists on the chef-brigade flavor of the cookbook as we can actively make changes to resolve any issues.
We're currently using chef to provision our servers and we want our recipe/cookbook to automatically add some data to the mongo database once its installed and running.
This is where we start to run into problems. We were using an execute resource to run the mongo script like this:
execute "install-mongodb-config" do
command "mongo #{node[:mongodb][:mongo_db_host]}/#{node[:mongodb][:mongo_db]} \"#{node[:mongodb][:mongo_add_config_script]}\""
action :run
end
This part of the recipe always failed no matter what we tried! I won't get into the details of everything we tried here (unless i need to) but lets just say that i've exhausted all possibilities of subscribes and notifies (i think).
The problem originates from the fact that we are using the mongodb::10gen_repo to install mongodb. The recipe exits when apt-get installs the package and then chef continues on to execute more resourses.
We have tried executing the above resource directly after mongodb::10gen_repo but it doesn't seem like mongodb is available and the mongo shell cannot connect and run the script. The error we see is somewhat like this:
MongoDB shell version: 2.0.2
Thu Sep 6 18:40:45 ReferenceError: setTimeout is not defined mongotest.js:2
failed to load: mongoAddConfig.js
Nothing we have tried has been able to get around this in a nice chef way. The thing that we resorted to was to replace the execute resource with the following:
execute "install-mongodb-config" do
command "sleep 60; mongo #{node[:mongodb][:mongo_db_host]}/#{node[:mongodb][:mongo_db]} \"#{node[:mongodb][:mongo_add_config_script]}\""
action :run
end
Which just makes the command sleep for 60 seconds before the mongo script is run. I know this isn't the Right way to do this but it works for now.
Can anyone suggest the Right way to do this? I have a feeling that I will need to talk to the guys that created the mongodb chef script and request a feature!
First of all. Remove this "sleep 60". This can be done by chef: All resources have common attributes and "retries" and "retry_delay" are part of them. So the easiest way would be:
execute "install-mongodb-config" do
command "mongo some_command"
action :run
retries 6
retry_delay 10
end
If you have more than 2-3 places, where you have to run some command on mongo database, consider creating LWRP, similar to one created in this mongodb cookbook. (Particularly check the libraries/mongodb.rb file). You can hide the logic that waits for the server to respond there.
Is it important that the same Chef run that installs the software also injects the initial configuration? The 'chefly' method to constructing cookbooks and recipes is to guard against idempotency in order to ensure that they can be run over and over again without producing unintended results.
In this particular case, I would limit the first recipe to only just installing and starting up mongodb. This recipe would do nothing if it saw that mongodb was already running on the host. Then, I'd have another recipe that would run only if it saw that mongo had been setup and was running. It would query the mongodb to see if the initial configuration had been done. If so, it would simply return. If not, it would run your configuration routine.
In this way, these recipes could run all the time, anytime, on your machine. Even if someone uninstalled mongodb, chef would get around to ensuring that it was set back up again and pristine.
So, I don't know much at all about chef. But your problem seems to be that you try to immediately connect after bringing the server up.
Server's are not immediately available when you bring them up since there is a bit of overhead that goes into electing a primary, getting all the server status's etc.
You can recreate this without chef by trying to bring up a replica set and immediately trying to connect to it in a simple script. So it's not chef specific.
Not sure if there is a way around the server startup lag since bringing up a primary is expected to be a relatively infrequent occurrence compared to just adding nodes to a set.
The only potential solution I see that is cleaner is adding a longer Timeout for the connection to be formed in the configuration. You can find how to do this in the mongodb documentation here: http://www.mongodb.org/display/DOCS/Connections
The flag of interest for you is likely connectTimeoutMS
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