> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apinizer.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Cleaning notification_user Collection

> Enables cleaning old records from the notification_user collection where user notifications are kept, according to the specified time period.

<Warning>
  Time filter is based on UTC.
</Warning>

## Record Cleanup Script

The following script is used to delete records older than the specified time from the `notification_user` collection stored in MongoDB. This operation optimizes storage space by cleaning the database.

```bash theme={null}
#!/bin/bash
  
# Information required to connect to MongoDB server
HOST="<MONGODB_MASTER_IP_ADDRESS>"
PORT="<MONGODB_PORT>"
DB_NAME="apinizerdb"
USERNAME="apinizer"
PASSWORD="<PASSWORD>"
AUTH_DB="admin"
TARGET_COLLECTION="notification_user"
TARGET_LOG_LOCATION=$(pwd)/purge_apinizer_log_collection.log
  
echo "Script started on $(date +"%Y-%m-%d %H:%M:%S")" >> $TARGET_LOG_LOCATION
  
# Variable indicating how many hours/days ago records will be deleted
TIME_VALUE="1D"  #You can change this value as you wish.
  
# Analyze TIME_VALUE and convert to milliseconds
if [[ $TIME_VALUE =~ [Hh]$ ]]; then
    HOURS_AGO=${TIME_VALUE%H*}
    TIME_IN_MILLISECONDS=$(($HOURS_AGO * 60 * 60 * 1000))
elif [[ $TIME_VALUE =~ [Dd]$ ]]; then
    DAYS_AGO=${TIME_VALUE%D*}
    TIME_IN_MILLISECONDS=$(($DAYS_AGO * 24 * 60 * 60 * 1000))
else
    echo "Invalid time format. Please enter a value ending with H (hour) or D (day)." >> $TARGET_LOG_LOCATION
    exit 1
fi
  
MONGO_COMMANDS=$(cat <<EOF
var dateToRemove=new Date((new Date().getTime() - $TIME_IN_MILLISECONDS));
var bulk = db.getCollection("$TARGET_COLLECTION").initializeUnorderedBulkOp();
bulk.find( {"createdTime":{"\$lt": dateToRemove}}).remove();
bulk.execute();
EOF
)
  
# Execute command and write output to log file
{
    mongosh mongodb://$USERNAME:$PASSWORD@$HOST:$PORT/$DB_NAME --authenticationDatabase $AUTH_DB --eval "$MONGO_COMMANDS"
    # Check if command completed
    if [ $? -ne 0 ]; then
        echo "MongoDB command failed." >> $TARGET_LOG_LOCATION
        exit 1
    fi
} >> $TARGET_LOG_LOCATION 2>&1
  
echo "The command has been executed. Please check the content of the related collection." >> $TARGET_LOG_LOCATION
  
echo "Script finished on $(date +"%Y-%m-%d %H:%M:%S")" >> $TARGET_LOG_LOCATION
```

## How It Works

<Steps>
  <Step title="Defining MongoDB Connection Information">
    Information required to connect to MongoDB server is defined in relevant variables: HOST, PORT, DB\_NAME, USERNAME, PASSWORD, and AUTH\_DB.
  </Step>

  <Step title="Determining Time Period">
    The TIME\_VALUE variable specifies how many hours ago records will be deleted. This value can be in hours (H) or days (D).
  </Step>

  <Step title="Preparing MongoDB Commands">
    MongoDB commands are defined in the MONGO\_COMMANDS variable to find and delete documents older than the specified time.
  </Step>

  <Step title="Executing Commands">
    Connect to MongoDB server using the mongosh command and execute the commands defined in the MONGO\_COMMANDS variable.
  </Step>

  <Step title="Checking Results">
    When the operation is completed, the message "The command has been executed. Please check the content of the related collection." is printed to the screen.
  </Step>
</Steps>

## Usage

Before running the script, enter your own information in the MongoDB variables. You can update the TIME\_VALUE variable according to your desired hour/day value. For example:

* To keep documents from the last 3 hours and delete the rest: `TIME_VALUE=3H`
* To keep documents from the last 5 days and delete the rest: `TIME_VALUE=5D`

To run the script on a Linux-based operating system:

1. Copy the script to a file using a text editor (vi, nano, etc.) and edit the variables inside
2. Give execute permission to the file: `chmod +x purge_notification_user_collection.sh`
3. Run the file: `./purge_notification_user_collection.sh`

If you think the operation will take a long time, you can make it run in the background by adding a space and the `&` character at the end of the command:

```bash theme={null}
chmod +x /path/to/purge_notification_user_collection.sh
./path/to/purge_notification_user_collection.sh &
```

This operation can be done manually or repeated at certain intervals. To repeat it, this record must be added to linux cronjob settings.

## CronJob Usage

<Steps>
  <Step title="Opening Cron Editor">
    Open the cron editor by running the following command in the terminal:

    ```bash theme={null}
    crontab -e
    ```
  </Step>

  <Step title="Adding Cron Job">
    Add a line to the opened editor according to how often you want to run the script.

    For example, to run it every day at 23:59:

    ```bash theme={null}
    59 23 * * * /path/to/purge_notification_user_collection.sh > /path/to/logfile.log 2>&1
    ```
  </Step>

  <Step title="Saving">
    Press Esc and type :wq and press Enter to save the line you added.
  </Step>
</Steps>

<Info>
  Data cleanup operation will be performed according to the time period you specified in the script. Therefore, it is important to ensure that the time period in the script and the trigger time you set with cron are consistent.
</Info>