```

### 3.2 Automatic removal of noncurrent versions keeping only most recent ones after noncurrent days

It is possible to configure automatic removal of older noncurrent versions keeping only the most recent `N` using `NewerNoncurrentVersions`.

e.g, To remove noncurrent versions of all objects keeping the most recent 5 noncurrent versions under the prefix `user-uploads/` 30 days after they become noncurrent ,

	recursive    bool       `msg:"rec"`
	dataVersion  uint8      `msg:"v"`
}

func (m *metacache) finished() bool {
	return !m.ended.IsZero()
}

// worthKeeping indicates if the cache by itself is worth keeping.
func (m *metacache) worthKeeping() bool {
	if m == nil {
		return false
	}
	cache := m
	switch {
	case !cache.finished() && time.Since(cache.lastUpdate) > metacacheMaxRunningAge:

Contributing
============

Keeping the project small and stable limits our ability to accept new contributors. We are not
seeking new committers at this time, but some small contributions are welcome.

If you've found a security problem, please follow our [bug bounty][security] program.

If you've found a bug, please contribute a failing test case so we can study and fix it.

If you have a new feature idea, please build it in an external library. There are

Contributing
============

Keeping the project small and stable limits our ability to accept new contributors. We are not
seeking new committers at this time, but some small contributions are welcome.

If you've found a security problem, please follow our [bug bounty][security] program.

If you've found a bug, please contribute a failing test case so we can study and fix it.

If you have a new feature idea, please build it in an external library. There are

    // 3) Caller specified but assuming the visible defaults in MODERN_CIPHER_SUITES are rejigged
    // to match legacy i.e. the platform/provider
    //
    // Opting for 2 here and keeping MODERN_TLS in line with secure browsers.
    cipherSuitesAsString.intersect(socketEnabledCipherSuites, CipherSuite.ORDER_BY_NAME)
  } else {
    socketEnabledCipherSuites
  }
}

code is a great way to give something back to the open source community. Before
you dig right into the code, there are a few guidelines that we need
contributors to follow so that we can have a chance of keeping on top of
things.

Some of the ideas are documented in the [Maven Wiki][maven-wiki]
which might be interesting to read and for further discussion.

Getting Started
---------------

Goals:
- Improve upgrade experience: users should be able to gradually roll upgrades, with proper
canary deployments for Istio components. It should be possible to deploy a new version while keeping the
stable version in place and gradually migrate apps to the new version.

- More flexibility: the new installer allows multiple 'environments', allowing applications to select

	// Test on a copy
	// cleanup is the only one deleting caches.
	caches, _ := b.cloneCaches()

	for id, cache := range caches {
		if !cache.worthKeeping() {
			b.debugf("cache %s not worth keeping", id)
			remove[id] = struct{}{}
			continue
		}
		if cache.id != id {
			logger.Info("cache ID mismatch %s != %s", id, cache.id)
			remove[id] = struct{}{}
			continue
		}

   while also keeping file watchers on them. Envoy proxy then connects to istio-agent's SDS Server through the defined socket path and gets the cryptographic materials of the certificate files served by the SDS API.

		p.actionsLatency[a].add(duration)
	}
}

type currentPathTracker struct {
	name *unsafe.Pointer // contains atomically accessed *string
}

// currentPathUpdater provides a lightweight update function for keeping track of
// current objects for each disk.
// Returns a function that can be used to update the current object
// and a function to call to when processing finished.