I have been logging bitcoin order books and trades for the past 20 days in mongodb. 1 database [bitmicro], 1 collection for trades, 1 collection for books.
now suddently all the data is gone and the logger has started from scratch since yesterday.
The mongo log doesnt show any entries since October. And a new database appeared called Warning exactly when the data loss happened
> show dbs
Warning 0.078GB
bitmicro 0.453GB
local 0.078GB
After some reading it might be the case, that the filesize of the collection became too big and ubuntu deleted it?
Since the log /var/log/mongodb/mongod.log doesnt show any entries since starting the server, how can I find out what happened?
the existence of the Warning database implies that your database was accessed by a malicious 3rd party, and your database is exposed to the internet without any authentication.
https://docs.mongodb.com/manual/administration/security-checklist/
Related
I have several databases under the mongodb instance (v 4.0.26) in a Ubuntu 18.04 server.
One of the database has started behaving inconsistently in terms of connectivity all of a sudden.
I have checked the resource consumption on the server. 7GB of RAM left and 34GB of storage also available.
In Mongo Shell (at the server), when I connect to the particular database and perform db.getCollectionNames() it just hangs. This behavior is also not consistent. But every other database in that instance works without any problem.
I am suspecting there could be a corrupt document in any of the collection which is resulting this. Looking for guidance to debug this issue.
P.S.: Losing the data in db might cost my job.
good day to you all.
I am currently having a hard time restoring the MongoDB database.
Here is what happened.
Thanks for looking into this matter
Basically, my server and MongoDB 3.2 server running on DigitalOcean.
I made some changes on mongod.conf file to allow remote access from my local machine. Since then, it no longer worked. I got Mongodb connection failed issue so reinstalled new Mongodb version 4.4 and it doesn't want to load existing data which is located in var/lib/MongoDB. So I downloaded the whole data files as posted above on my local machine.
Now, at least I want to open the current database on my local machine but I couldn't find any proper way to achieve this. Thanks again for looking into this issue.
I use MongoDB 4.2 on my local machine (windows 10). I have not changed any configurations, so the default behavior of only accepting local connections should be in place. (I only need to access it locally)
I was running a script that was reading data from my MongoDB, there are no writes to the db in this script. When all the numbers were crunched I noticed weird results, and saw that my database was suddenly gone. I checked my dbpath and the data was gone from there too! Could it be a hack, or was it MongoDB that dropped both the database and the raw data in the dbpath?
I've seen similar questions on this forum, mostly resolved by the author forgetting to reroute to the correct dbpath, which is not the case here. I've checked the log but the log seems to be very limited (I restarted mongod and could only see logging happening after the restart).
MongoDB does not delete all of the files in its data directory.
Most likely either you are checking in the wrong place or something external to MongoDB deleted its files.
I am using mongodb 3.2.11 in Ubuntu Zesty 17.04 and I am connecting from Nodejs 4.6 to mongodb in HTTPS, the database server is bound to its own address (127.0.0.1) and I have created a user besides admin for read/write to the database.
Although, most of my tables were certainly dropped somehow, only users (empty) and sessions table were left.
I grepped my logs for "drop" with grep -r "drop" and got no results. Despite I am using very recent versions of the software and made some security measures they don't seem enough. At this time I don't need to recover the data, but I wanted to know what else should I be looking at?
Try to use "show collections" in the mongo shell in ubuntu and see if the collections are shown after doing "use dbnamehere".
We have a three-server replicaset running MongoDB 2.2 on Ubuntu 10.04, and recently had to upgrade the hard drive for each server where one particular database resides. This database contains log information for web service requests, where they write to collections in hourly buckets using the current timestamp to determine the name, e.g. log_yyyymmddhh.
I performed this process:
backup the database on the primary server with mongodump --db log_db
take a secondary server offline, replace the disk
bring the secondary server up in standalone mode (i.e. comment out the replSet entry
in /etc/mongodb.conf before starting the service)
restore the database on the secondary server with mongorestore --drop --db log_db
add the secondary server back into the replicaset and bring it online,
letting replication catch up the hourly buckets that were updated/created
while it had been offline
Everything seemed to go as expected, except that the collection which was the current bucket at the time of the backup was not brought up to date by replication. I had to manually copy that collection over by hand to get it up to date. Note that collections which were created after the backup were synched just fine.
What did I miss in this process that caused MongoDB not to get things back in synch for that one collection? I assume something got out of whack with regard to the oplog?
Edit 1:
The oplog on the primary showed that its earliest timestamp went back a couple of days, so there should have been plenty of space to maintain transactions for a few hours (which was the time the secondary was offline).
Edit 2:
Our MongoDB installation uses two disk partitions: /dev/sda1 and /dev/sdb1. The primary MongoDB directory /var/lib/mongodb/ is on /dev/sda1, and holds several databases, while the log database resides by itself on /dev/sdb1. There's a sym link /var/lib/mongodb/log_db which points to a directory on /dev/sdb1. Since the log db was getting full, we needed to upgrade the disk for /dev/sdb1.
You should be using mongodump with the --oplog option. Running a full database backup with mongodump on a replicaset that is updating collections at the same time may not leave you with a consistent backup. This becomes worse with larger databases, more collections and more frequent updates/inserts/deletes.
From the documentation for your version (2.2) of MongoDB (it's the same for 2.6 but just to be as accurate as possible):
--oplog
Use this option to ensure that mongodump creates a dump of the
database that includes an oplog, to create a point-in-time snapshot of
the state of a mongod instance. To restore to a specific point-in-time
backup, use the output created with this option in conjunction with
mongorestore --oplogReplay.
Without --oplog, if there are write operations during the dump
operation, the dump will not reflect a single moment in time. Changes
made to the database during the update process can affect the output
of the backup.
http://docs.mongodb.org/v2.2/reference/mongodump/
This is not covered well in most MongoDB tutorials around backups and restores. Generally you are better off if you can perform a live snapshot of the storage volume your database resides on (assuming your storage solution has a live snapshot ability compatible with MongoDB). Failing that, your next best bet is taking a secondary offline and then performing a snapshot or backup of the database files. Mongodump on a live database is increasingly a less optimal solution for larger databases due to performance issues.
I'd definitely take a look at the MongoDB overview of backup options: http://docs.mongodb.org/manual/core/backups/
I would guess this has to do with the oplog not being long enough, although it seems like you checked that and it looked reasonably big.
Still, when adding new members to a replica set you shouldn't be snapshotting and restoring them. It's better to simply add a new member and let replication happen by itself. This is described in the Mongo docs and is the process I've always followed.