Updating MongoDB 3.6 to 4.4¶

Due to incompatibility of the MongoDB service versions 3.6 and 4.4 you have to export the stored data before updating and reimport them afterwards.

Hint - single system and cluster

The following instructions include the update of both, single system and cluster.

In a single system, perform all instructions, except of those concerning the replica set.

In a cluster, perfom the instructions as stated in the subchapters.

Saving the Database Content¶

Hint - cluster

In a cluster, you have to perform the following instructions on the replica set primary only.

Open a PowerShell (Administrator).
In the %TEMP% directory, create a mongodump subdirectory, if it does not yet exist:
```
cd $env:TEMP
mkdir mongodump
```
Start MongoDB, if necessary:
```
Start-Service seal-mongodb
```

Save the stored data:

& "C:\Program Files\MongoDB\Server\3.6\bin\mongodump.exe" --ssl --sslAllowInvalidCertificates --out "$env:TEMP\mongodump"

Hint - cluster

In a cluster, you have to perform the following instructions except of the initializing of the database on every member of the replica set.

Caution - update member of the replica set

Make sure that all cluster members are upgraded and reconfigured before you restore the database.

Stop MongoDB:
```
Stop-Service seal-mongodb -Force
```
Remove all subdirectories and files in the C:\ProgramData\SEAL Systems\data\seal-mongodb directory, except of the base directory itself:
```
Remove-Item "C:\ProgramData\SEAL Systems\data\seal-mongodb\*" -Force -Recurse
```
Install MongoDB.
Reconfigure the shared replica set.
Reinitialize the database - only on single systems and the replica set primary.
Reconnect the database servers to the cluster.

Hint - cluster

In a cluster, you have to perform the following instructions on the replica set primary only.

Remove-Item "$env:TEMP\mongodump\admin" -Force -Recurse

Restore the data:

& "C:\Program Files\MongoDB\Tools\100\bin\mongorestore.exe" /ssl /tlsInsecure /drop "$env:TEMP\mongodump"