# MinIO Monitoring Guide

MinIO server exposes monitoring data over endpoints. Monitoring tools can pick the data from these endpoints. This document lists the monitoring endpoints and relevant documentation.

## Healthcheck Probe

MinIO server has two healthcheck related un-authenticated endpoints, a liveness probe to indicate if server is responding, cluster probe to check if server can be taken down for maintenance.

// the directory itself, if the dirPath doesn't exist this function doesn't return
// an error.
func readDirFn(dirPath string, filter func(name string, typ os.FileMode) error) error {
	// Ensure we don't pick up files as directories.
	globAll := filepath.Clean(dirPath) + `\*`
	globAllP, err := syscall.UTF16PtrFromString(globAll)
	if err != nil {
		return errInvalidArgument
	}
	data := &syscall.Win32finddata{}

      olderThan: 70h # match objects older than this value
      createdBefore: "2006-01-02T15:04:05.00Z" # match objects created before "date"
      tags:
        - key: name
          value: pick* # match objects with tag 'name', all values starting with 'pick'
      metadata:
        - key: content-type
          value: image/* # match objects with 'content-type', all values starting with 'image/'
      size:

// as an error to be reported.
func readAllInto(b []byte, r *wsutil.Reader) ([]byte, error) {
	for {
		if len(b) == cap(b) {
			// Add more capacity (let append pick how much).
			b = append(b, 0)[:len(b)]
		}
		n, err := r.Read(b[len(b):cap(b)])
		b = b[:len(b)+n]
		if err != nil {
			if errors.Is(err, io.EOF) {
				err = nil
			}
			return b, err
		}
	}

	  createdBefore: "date" # match objects created before "date"

	  ## NOTE: tags are not supported when "source" is remote.
	  # tags:
	  #   - key: "name"
	  #     value: "pick*" # match objects with tag 'name', with all values starting with 'pick'

	  ## NOTE: metadata filter not supported when "source" is non MinIO.
	  # metadata:
	  #   - key: "content-type"

	} else {
		reducedErr = reduceReadQuorumErrs(ctx, errs, objectOpIgnoredErrs, readQuorum)
	}
	if reducedErr != nil {
		return fi, nil, reducedErr
	}

	// Pick one from the first valid metadata.
	fi, err = pickValidFileInfo(ctx, partsMetadata, modTime, etag, quorum)
	return fi, partsMetadata, err
}

| ![Dashboard](https://github.com/minio/minio/blob/master/docs/screenshots/pic1.png?raw=true) | ![Dashboard](https://github.com/minio/minio/blob/master/docs/screenshots/pic2.png?raw=true) |

## Test using MinIO Client `mc`

This parameter can be set to `ldap` or `ldaps` and MinIO will substitute it into the `service` value. For example, when `server_addr=myldapserver.com` and `srv_record_name=ldap`, MinIO will lookup the SRV record for `_ldap._tcp.myldapserver.com` and pick an appropriate target for LDAP requests.

If the DNS SRV record is at an entirely different place, say `_ldapsrv._tcpish.myldapserver.com`, then set `srv_record_name` to the special value `on` and set `server_addr=_ldapsrv._tcpish.myldapserver.com`....

		return input.Clone(output), nil
	}

	for i, expr := range e.selectAST.Expression.Expressions {
		v, err := expr.evalNode(input, e.tableAlias)
		if err != nil {
			return nil, err
		}

		// Pick output column names
		if expr.As != "" {
			output, err = output.Set(expr.As, v)
		} else if comp, ok := getLastKeypathComponent(expr.Expression); ok {
			output, err = output.Set(comp, v)
		} else {

	// To avoid these problems we must split the work at scale. With 1000 node
	// setup becoming a reality we must try to shard the work properly such as
	// pick 10 nodes that precisely can send those 100 requests the first node
	// in the 10 node shard would coordinate between other 9 shards to get the
	// rest of the `99*9` requests.
	//