watchCacheInterval serves as an abstraction over a source
of watchCacheEvents. It maintains a window of events over
an underlying source and these events can be served using
the exposed Next() API. The main intent for doing things
this way is to introduce an upper bound of memory usage
for starting a watch and reduce the maximum possible time
interval for which the lock would be held while events are
copied over.
The source of events for the interval is typically either
the watchCache circular buffer, if events being retrieved
need to be for resource versions > 0 or the underlying
implementation of Store, if resource version = 0.
Furthermore, an interval can be either valid or invalid at
any given point of time. The notion of validity makes sense
only in cases where the window of events in the underlying
source can change over time - i.e. for watchCache circular
buffer. When the circular buffer is full and an event needs
to be popped off, watchCache::startIndex is incremented. In
this case, an interval tracking that popped event is valid
only if it has already been copied to its internal buffer.
However, for efficiency we perform that lazily and we mark
an interval as invalid iff we need to copy events from the
watchCache and we end up needing events that have already
been popped off. This translates to the following condition:
watchCacheInterval::startIndex >= watchCache::startIndex.
When this condition becomes false, the interval is no longer
valid and should not be used to retrieve and serve elements
from the underlying source.
Signed-off-by: Madhav Jivrajani <madhav.jiv@gmail.com>
Kubernetes-commit: 347607e97139959f33024a691d0561b1479aeeef
In the following code pattern, the log message will get logged with v=0 in JSON
output although conceptually it has a higher verbosity:
if klog.V(5).Enabled() {
klog.Info("hello world")
}
Having the actual verbosity in the JSON output is relevant, for example for
filtering out only the important info messages. The solution is to use
klog.V(5).Info or something similar.
Whether the outer if is necessary at all depends on how complex the parameters
are. The return value of klog.V can be captured in a variable and be used
multiple times to avoid the overhead for that function call and to avoid
repeating the verbosity level.
Kubernetes-commit: 9eaa2dc554e0c3d4485d4c916dfdbc2f517db2e0
Split process() function into processEvents() and process().
This is done in anticipation of GetAllEventsSinceThreadUnsafe()
returning an entity using which events can be constructed and
not the events itself.
Subsequently, this commit also moves updating resource version
for initEvents from Watch() to the processEvents() func.
Signed-off-by: Madhav Jivrajani <madhav.jiv@gmail.com>
Kubernetes-commit: aab7cd3d8a66f425022ca5b2a2bd0d3019efe526
This PR enables unaryClientInterceptor in conjunction with Prometheus interceptor.
Previously it was simply overwritten by the Prometheus interceptor.
As a result etcd client didn't attempt to retry certain errors.
The unaryClientInterceptor is important because it knows how to retry all sorts of errors from the etcd cluster. It will make the API server more resilient to failures - end users won't see certain errors.
The full list of retriable (codes.Unavailable) errors can be found at https://github.com/etcd-io/etcd/blob/main/api/v3rpc/rpctypes/error.go#L72
Kubernetes-commit: 83171562b0954b2e19eb69943f01a44779cc7a8f
This is a Config specialized for a GroupResource.
It will support generating new resource-specific metrics.
Kubernetes-commit: 85bcd243aa3c8769a5904a1aea44ce704f5e7174
instead of using a goroutine refreshing the budget, obtain
the value from the last time the budget was accessed.
Kubernetes-commit: dd2c38306000eeb1720afc8346165a6caab09259
Madhav Jivrajani