Removed anycast functionality from traffic control (#62)

* removed anycast functionality from traffic control

* added changelog for pr

* corrected formatting in traffic_monitor/datareq/datareq.go

---------

Co-authored-by: serDrem <[email protected]>

CHANGELOG.md

@@ -9,6 +9,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 - [#7870](https://github.com/apache/trafficcontrol/pull/7870) *Traffic Portal*: Adds a hyperlink to the DSR page to the DS itself for ease of navigation.
 
 ### Changed
+- [#62] (https://github.com/comcast-cdn/trafficcontrol/pull/62) *Traffic Monitor, Documentation* Removed anycast functionality from traffic control
 - [#7614](https://github.com/apache/trafficcontrol/pull/7614) *Traffic Ops* The database upgrade process no longer overwrites changes users may have made to the initially seeded data.
 - [#7832](https://github.com/apache/trafficcontrol/pull/7832) *t3c* Removed perl dependency
 - Updated the CacheGroups Traffic Portal page to use a more performant AG-Grid-based table.

docs/source/admin/traffic_monitor.rst

@@ -79,7 +79,6 @@ traffic_monitor.cfg
 - ``health.polling.interval``
 - ``peers.polling.interval``
 - ``heartbeat.polling.interval``
-- ``tm.sameipservers.enabled`` - When set to true, performs an AND operation on the availability statuses of servers with same ip. Any unavailable server(s) with same ip as other server(s) will cause the other server(s) to be set to unavailable.
 
 Upon receiving this configuration, Traffic Monitor begins polling :term:`cache server` s. Once every :term:`cache server` has been polled, :ref:`health-proto` state is available via RESTful JSON endpoints and a web browser UI.
 

docs/source/glossary.rst

@@ -41,11 +41,6 @@ Glossary
 		- :term:`forward proxy`: Used by Traffic Control for Mid-tier :dfn:`cache servers`.
 		- transparent proxy: These are not used by Traffic Control. If you are interested you can learn more about transparent proxies on `wikipedia <http://en.wikipedia.org/wiki/Proxy_server#Transparent_proxy>`_.
 
-	anycast group
-	Anycast group
-	Anycast Group
-        A group of caching HTTP proxy servers that have the same service address that is equal cost multi path routed at the last hop
-
 	Cache Group
 	Cache Groups
 		A group of caching HTTP proxy servers that together create a combined larger cache using consistent hashing. Traffic Router treats all servers in a :dfn:`Cache Group` as though they are in the  same geographic location, though they are in fact only in the same general area. A :dfn:`Cache Group` has one single set of geographical coordinates even if the :term:`cache servers` that make up the :dfn:`Cache Group` are actually in :term:`Physical Locations`. The :term:`cache servers` in a :dfn:`Cache Group` are not aware of the other :term:`cache servers` in the group - there is no clustering software or communications between :term:`cache servers` in a :dfn:`Cache Group`.

docs/source/overview/traffic_monitor.rst

@@ -55,7 +55,3 @@ The optimistic quorum prevents invalid state propagation caused by a Traffic Mon
 Protocol Engagement
 -------------------
 Short polling intervals of both the :term:`cache servers` and Traffic Monitor peers help to reduce customer impact of outages. It is not uncommon for a :term:`cache server` to be marked unavailable by Traffic Monitor - in fact, it is business as usual for many CDNs. Should a widely requested video asset cause a single :term:`cache server` to get close to its interface capacity, the Health Protocol will "kick in," and Traffic Monitor marks the :term:`cache server` as unavailable. New clients want to see the same asset, and now :ref:`tr-overview` will send these customers to another :term:`cache server` in the same :term:`Cache Group`. The load is now shared between the two :term:`cache servers`. As clients finish watching the asset on the overloaded :term:`cache server`, it will drop below the threshold and gets marked available again, and new clients will begin to be directed to it once more. It is less common for a :term:`Delivery Service` to be marked unavailable by Traffic Monitor. The :term:`Delivery Service` thresholds are usually used for overflow situations at extreme peaks to protect other :term:`Delivery Services` in the CDN from being impacted.
-
-Handling Cache Servers with Same Service IP
--------------------------------------------
-Traffic Monitor is able to direct Traffic Router to route traffic to groups of :term:`cache servers` with the same service IP address, but not to an individual :term:`cache server` within that group. To monitor :term:`cache servers` within that group, HTTP :mailheader:`Keep-Alive` header is omitted with the ``health.polling.keepalive`` and ``stat.polling.keepalive`` Traffic Monitor :term:`profile` :term:`parameters` so that the Traffic Monitor source port changes for those connections and the Traffic Monitor can get to all the :term:`cache servers` within that group via `ECMP <https://en.wikipedia.org/wiki/Equal-cost_multi-path_routing>`(Equal Cost Multi Path). ECMP rules govern routing to destinations with equal cost. Changing the source port ensures all the routes to :term:`cache servers` within an ECMP group are taken. Then Traffic Monitor updates the responses using the :mailheader:`Via` header. In the event of :dfn:`Health Protocol` determining the overall health of one of the :term:`cache servers` in an anycast group by evaluating network throughput and load against values configured in :ref:`to-overview` to exceed their limit, it declares the whole groups as unhealthy.

lib/go-rfc/http.go

@@ -43,7 +43,6 @@ const (
 	Age                = "Age"                 // RFC7234§5.1
 	Location           = "Location"            // RFC7231§7.1.2
 	Authorization      = "Authorization"       // RFC7235§4.2
-	Via                = "Via"                 // RFC3261§8.1.1.7
 	Cookie             = "Cookie"              // RFC7873
 )
 

lib/go-tc/crstates.go

@@ -44,7 +44,6 @@ type IsAvailable struct {
 	DirectlyPolled bool      `json:"-"`
 	Status         string    `json:"status"`
 	LastPoll       time.Time `json:"lastPoll"`
-	LastPollV6     time.Time `json:"lastPollV6"`
 }
 
 // NewCRStates creates a new CR states object, initializing pointer members.

traffic_monitor/cache/astats.go

@@ -33,21 +33,17 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"regexp"
 	"strings"
 
 	"github.com/apache/trafficcontrol/v8/lib/go-log"
-	"github.com/apache/trafficcontrol/v8/lib/go-rfc"
 	"github.com/apache/trafficcontrol/v8/traffic_monitor/dsdata"
 	"github.com/apache/trafficcontrol/v8/traffic_monitor/poller"
 	"github.com/apache/trafficcontrol/v8/traffic_monitor/todata"
-
 	jsoniter "github.com/json-iterator/go"
 )
 
 func init() {
 	registerDecoder("astats", astatsParse, astatsPrecompute)
-	hostnameRegex = regexp.MustCompile(`(?:http|https)/\d+\.\d+ ([A-Za-z0-9\-]{0,61})`)
 }
 
 // AstatsSystem represents fixed system stats returned from the
@@ -120,22 +116,8 @@ func astatsParse(cacheName string, rdr io.Reader, pollCTX interface{}) (Statisti
 		astats.Ats["system.proc.loadavg"] = astats.System.ProcLoadavg
 		astats.Ats["system.proc.net.dev"] = astats.System.ProcNetDev
 
-		via := ctx.HTTPHeader.Get(rfc.Via)
-		if via != "" {
-			viaRegexSubmatch := hostnameRegex.FindStringSubmatch(via)
-			if len(viaRegexSubmatch) > 0 {
-				astats.Ats[rfc.Via] = viaRegexSubmatch[1]
-			}
-		}
 		return stats, astats.Ats, nil
 	} else if ctype == "text/csv" {
-		via := ctx.HTTPHeader.Get(rfc.Via)
-		if via != "" {
-			viaRegexSubmatch := hostnameRegex.FindStringSubmatch(via)
-			if len(viaRegexSubmatch) > 0 {
-				cacheName = viaRegexSubmatch[1]
-			}
-		}
 		return astatsCsvParseCsv(cacheName, rdr)
 	} else {
 		return stats, nil, fmt.Errorf("stats Content-Type (%s) can not be parsed by astats", ctype)

traffic_monitor/cache/astats_csv.go

@@ -28,7 +28,6 @@ import (
 	"strings"
 
 	"github.com/apache/trafficcontrol/v8/lib/go-log"
-	"github.com/apache/trafficcontrol/v8/lib/go-rfc"
 )
 
 type astatsDataCsv struct {
@@ -129,7 +128,5 @@ func astatsCsvParseCsv(cacheName string, data io.Reader) (Statistics, map[string
 		return stats, nil, fmt.Errorf("cache '%s' had no interfaces", cacheName)
 	}
 
-	statMap[rfc.Via] = cacheName
-
 	return stats, statMap, nil
 }

traffic_monitor/cache/cache.go

@@ -20,13 +20,10 @@ package cache
  */
 
 import (
-	"fmt"
 	"io"
-	"regexp"
 	"time"
 
 	"github.com/apache/trafficcontrol/v8/lib/go-log"
-	"github.com/apache/trafficcontrol/v8/lib/go-rfc"
 	"github.com/apache/trafficcontrol/v8/lib/go-tc"
 	"github.com/apache/trafficcontrol/v8/traffic_monitor/todata"
 )
@@ -37,8 +34,6 @@ type Handler struct {
 	ToData     *todata.TODataThreadsafe
 }
 
-var hostnameRegex *regexp.Regexp
-
 func (h Handler) ResultChan() <-chan Result {
 	return h.resultChan
 }
@@ -316,9 +311,6 @@ func (handler Handler) Handle(id string, rdr io.Reader, format string, reqTime t
 		}
 		result.Time = time.UnixMilli(int64(valInt))
 	}
-	if value, ok := miscStats[rfc.Via]; ok {
-		result.ID = fmt.Sprintf("%v", value)
-	}
 
 	result.Statistics = stats
 	result.Miscellaneous = miscStats

traffic_monitor/cache/data.go

@@ -64,10 +64,6 @@ type AvailableStatus struct {
 	UnavailableStat string
 	// Poller is the name of the poller which set this availability status.
 	Poller string
-	// Time of last poll
-	LastPoll time.Time
-	// Time of v6 last poll
-	LastPollV6 time.Time
 }
 
 // CacheAvailableStatuses is the available status of each cache.

traffic_monitor/cache/stats_over_http.go

@@ -25,12 +25,10 @@ import (
 	"fmt"
 	"io"
 	"math"
-	"regexp"
 	"strconv"
 	"strings"
 
 	"github.com/apache/trafficcontrol/v8/lib/go-log"
-	"github.com/apache/trafficcontrol/v8/lib/go-rfc"
 	"github.com/apache/trafficcontrol/v8/traffic_monitor/poller"
 	"github.com/apache/trafficcontrol/v8/traffic_monitor/todata"
 
@@ -55,7 +53,6 @@ const LOADAVG_SHIFT = 65536
 
 func init() {
 	registerDecoder("stats_over_http", statsOverHTTPParse, statsOverHTTPPrecompute)
-	hostnameRegex = regexp.MustCompile(`(?:http|https)/\d+\.\d+ ([A-Za-z0-9\-]{0,61})`)
 }
 
 type stats_over_httpData struct {
@@ -74,14 +71,6 @@ func statsOverHTTPParse(cacheName string, data io.Reader, pollCTX interface{}) (
 
 	ctx := pollCTX.(*poller.HTTPPollCtx)
 
-	via := ctx.HTTPHeader.Get(rfc.Via)
-	if via != "" {
-		viaRegexSubmatch := hostnameRegex.FindStringSubmatch(via)
-		if len(viaRegexSubmatch) > 0 {
-			cacheName = viaRegexSubmatch[1]
-		}
-	}
-
 	ctype := ctx.HTTPHeader.Get("Content-Type")
 
 	if ctype == "text/json" || ctype == "text/javascript" || ctype == "application/json" || ctype == "" {
@@ -105,8 +94,6 @@ func statsOverHTTPParse(cacheName string, data io.Reader, pollCTX interface{}) (
 
 	statMap := sohData.Global
 
-	statMap[rfc.Via] = cacheName
-
 	if stats.Loadavg, err = parseLoadAvg(statMap); err != nil {
 		return stats, nil, fmt.Errorf("Error parsing loadavg for cache '%s': %v", cacheName, err)
 	}

traffic_monitor/datareq/crstate.go

@@ -23,14 +23,10 @@ import (
 	"fmt"
 	"net/http"
 	"net/url"
-	"strings"
 
 	"github.com/apache/trafficcontrol/v8/lib/go-log"
 	"github.com/apache/trafficcontrol/v8/lib/go-tc"
-	"github.com/apache/trafficcontrol/v8/traffic_monitor/health"
 	"github.com/apache/trafficcontrol/v8/traffic_monitor/peer"
-	"github.com/apache/trafficcontrol/v8/traffic_monitor/threadsafe"
-	"github.com/apache/trafficcontrol/v8/traffic_monitor/todata"
 )
 
 func srvTRState(
@@ -39,13 +35,11 @@ func srvTRState(
 	combinedStates peer.CRStatesThreadsafe,
 	peerStates peer.CRStatesPeersThreadsafe,
 	distributedPollingEnabled bool,
-	toData todata.TODataThreadsafe,
-	monitorConfig threadsafe.TrafficMonitorConfigMap,
 ) ([]byte, int, error) {
 	_, raw := params["raw"]     // peer polling case
 	_, local := params["local"] // distributed peer polling case
 	if raw {
-		data, err := srvTRStateData(localStates, distributedPollingEnabled, toData, monitorConfig)
+		data, err := srvTRStateSelf(localStates, distributedPollingEnabled)
 		return data, http.StatusOK, err
 	}
 
@@ -64,11 +58,19 @@ func srvTRState(
 		}
 	}
 
-	data, err := srvTRStateData(combinedStates, local && distributedPollingEnabled, toData, monitorConfig)
+	data, err := srvTRStateDerived(combinedStates, local && distributedPollingEnabled)
 
 	return data, http.StatusOK, err
 }
 
+func srvTRStateDerived(combinedStates peer.CRStatesThreadsafe, directlyPolledOnly bool) ([]byte, error) {
+	if !directlyPolledOnly {
+		return tc.CRStatesMarshall(combinedStates.Get())
+	}
+	unfiltered := combinedStates.Get()
+	return tc.CRStatesMarshall(filterDirectlyPolledCaches(unfiltered))
+}
+
 func filterDirectlyPolledCaches(crstates tc.CRStates) tc.CRStates {
 	filtered := tc.CRStates{
 		Caches:          make(map[tc.CacheName]tc.IsAvailable),
@@ -82,63 +84,10 @@ func filterDirectlyPolledCaches(crstates tc.CRStates) tc.CRStates {
 	return filtered
 }
 
-func srvTRStateData(localStates peer.CRStatesThreadsafe, directlyPolledOnly bool, toData todata.TODataThreadsafe, monitorConfig threadsafe.TrafficMonitorConfigMap) ([]byte, error) {
-	if val, ok := monitorConfig.Get().Config["tm.sameipservers.enabled"]; ok && val.(string) == "true" {
-		localStatesC := updateStatusSameIpServers(localStates, toData)
-		if !directlyPolledOnly {
-			return tc.CRStatesMarshall(localStatesC)
-		}
-		return tc.CRStatesMarshall(filterDirectlyPolledCaches(localStatesC))
-	}
+func srvTRStateSelf(localStates peer.CRStatesThreadsafe, directlyPolledOnly bool) ([]byte, error) {
 	if !directlyPolledOnly {
 		return tc.CRStatesMarshall(localStates.Get())
 	}
-	return tc.CRStatesMarshall(filterDirectlyPolledCaches(localStates.Get()))
-}
-
-func updateStatusSameIpServers(localStates peer.CRStatesThreadsafe, toData todata.TODataThreadsafe) tc.CRStates {
-	localStatesC := localStates.Get()
-	toDataC := toData.Get()
-
-	for cache, _ := range localStatesC.Caches {
-		if _, ok := toDataC.SameIpServers[cache]; ok {
-			// all servers with same ip must be available if they are in reported state
-			allAvailableV4 := true
-			allAvailableV6 := true
-			allIsAvailable := true
-			for partner, _ := range toDataC.SameIpServers[cache] {
-				if partnerState, ok := localStatesC.Caches[partner]; ok {
-					// a partner host is reported but is marked down for exceeding a threshold
-					// this host also needs to be marked down to divert all traffic for their
-					// common ip
-					if strings.Contains(partnerState.Status, string(tc.CacheStatusReported)) &&
-						strings.Contains(partnerState.Status, health.TooHigh.String()) {
-						if !partnerState.Ipv4Available {
-							allAvailableV4 = false
-						}
-						if !partnerState.Ipv6Available {
-							allAvailableV6 = false
-						}
-						if !partnerState.IsAvailable {
-							allIsAvailable = false
-						}
-						if !allAvailableV4 && !allAvailableV6 && !allIsAvailable {
-							break
-						}
-					}
-				}
-			}
-			newIsAvailable := tc.IsAvailable{}
-			newIsAvailable.DirectlyPolled = localStatesC.Caches[cache].DirectlyPolled
-			newIsAvailable.Status = localStatesC.Caches[cache].Status
-			newIsAvailable.LastPoll = localStatesC.Caches[cache].LastPoll
-			newIsAvailable.LastPollV6 = localStatesC.Caches[cache].LastPollV6
-			newIsAvailable.IsAvailable = localStatesC.Caches[cache].IsAvailable && allIsAvailable
-			newIsAvailable.Ipv4Available = localStatesC.Caches[cache].Ipv4Available && allAvailableV4
-			newIsAvailable.Ipv6Available = localStatesC.Caches[cache].Ipv6Available && allAvailableV6
-
-			localStatesC.Caches[cache] = newIsAvailable
-		}
-	}
-	return localStatesC
+	unfiltered := localStates.Get()
+	return tc.CRStatesMarshall(filterDirectlyPolledCaches(unfiltered))
 }