Bit Rot, also known as data rot or silent data corruption is a data loss issue faced by disk drives today. Data on the drive may silently get corrupted without signaling an error has occurred, making bit rot more dangerous than a permanent hard drive failure.

MinIO's erasure coded backend uses high speed [HighwayHash](https://github.com/minio/highwayhash) checksums to protect against Bit Rot.

## How are drives used for Erasure Code?

A non-current object version is a version which is not the latest for a given object. It is possible to set up an automatic removal of non-current versions when a version becomes older than a given number of days.

e.g., To scan objects stored under `user-uploads/` prefix and remove versions older than one year.

```
{
    "Rules": [
        {
            "ID": "Removing all old versions",
            "Filter": {

Regular Reads will block until data is available, but not wait for a full buffer. 
Writes will block until there is space available and writes bigger than the buffer will wait for reads to make space.

`TryRead` and `TryWrite` are still available for non-blocking reads and writes.

To signify the end of the stream, close the ring buffer from the writer side with `rb.CloseWriter()`

be used to select a different 'environment'.

## Installing

The new installer is intended to be modular and very explicit about what is installed. It has
far more steps than the Istio installer - but each step is smaller and focused on a specific
feature, and can be performed by different people/teams at different times.

`STANDARD` storage class implies more parity than `REDUCED_REDUNDANCY` class. So, `STANDARD` parity drives should be

- Greater than or equal to 2, if `REDUCED_REDUNDANCY` parity is not set.
- Greater than `REDUCED_REDUNDANCY` parity, if it is set.

Parity blocks can not be higher than data blocks, so `STANDARD` storage class parity can not be higher than N/2. (N being total number of drives)

transition_workers              (number)    set the number of transition workers (default: '100')
stale_uploads_expiry            (duration)  set to expire stale multipart uploads older than this values (default: '24h')
stale_uploads_cleanup_interval  (duration)  set to change intervals when stale multipart uploads are expired (default: '6h')

The handler function has this signature.

Sample handler:
```go
    handler :=  func(ctx context.Context, payload []byte, in <-chan []byte, out chan<- []byte) *RemoteErr {
        fmt.Println("Got request with initial payload", p, "from", GetCaller(ctx context.Context))
        fmt.Println("Subroute:", GetSubroute(ctx))
        for {
            select {

- Supports object locking/retention across source and destination buckets natively out of the box, unlike AWS S3.
- Simpler implementation than [AWS S3 Bucket Replication Config](https://docs.aws.amazon.com/AmazonS3/latest/dev/replication-add-config.html) with requirements such as IAM Role, AccessControlTranslation, Metrics and SourceSelectionCriteria are not needed with MinIO.

            }
        }
    ]
}
```

## Publish MinIO events via Webhooks

[Webhooks](https://en.wikipedia.org/wiki/Webhook) are a way to receive information when it happens, rather than continually polling for that data.

### Step 1: Add Webhook endpoint to MinIO

  # optional flags based filtering criteria
  # for all source objects
  flags:
	filter:
	  newerThan: "7d" # match objects newer than this value (e.g. 7d10h31s)
	  olderThan: "7d" # match objects older than this value (e.g. 7d10h31s)
	  createdAfter: "date" # match objects created after "date"
	  createdBefore: "date" # match objects created before "date"