====== C ====== * Canary testing: * at Google, using a subset of real traffic to test the production performance of a new version * https://sre.google/workbook/canarying-releases/ * Elsewhere: serving a release to a predefined test population, as opposed to A/B which is statistics-based * [[wp>CIDR]] = Classless Inter-Domain Routing * A 1993 replacement for the legacy class-based (A, B, C..) IPv4 addressing architecture, replacing the old fixed size network addresses by sizes defined as powers of two, leading to the ''x.y.z.t/nn'' notation (''1 < nn < 23''), describing the number of bits making up the network part in an IP address, starting from the leftmost bits. * The largest network, with mask ''/0'' covers the entire IPv4 addressing space * The smallest network, with mask ''/32'' covers a single IPv4 address * In practice, GCP networks need a minimum of 4 reserved IP addresses, hence 8 to be practical, for a smallest network mask of ''32-log2(8) = /29'', and the largest network is a ''/16'' for 64 addresses. * Standardized as [[https://datatracker.ietf.org/doc/html/rfc4632|RFC 4632]] * Cloud Load Balancing * An umbrella product for GCP load balancing offerings * See [[gcp:m|Maglev]] * Compute Engine instance: a VM hosted on Google's infrastructure * Includes GKE clusters, AppEngine flexible environment instances, and other products build on Compute Engine VMs. * Cascading Failures: when one component fails to work, and alternate systems pick up the load, then get overwhelmed too. * Protect with degraded results, load shedding, graceful degradation * CFE = Cloud Front End. * Customer equivalent of [[gcp:g|GFE]]. * [[wp>CNCF]] = Cloud Native Computing Foundation * Correlated Failures: when related items fail simultaneously * Reduce impact by containerizing apps and implementing microservices that can run on multiple platforms. Ideally multi-zone or multi-region.