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vpaturetvpaturet
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Add HTTP response time metric
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+504
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‎application/src/main/java/org/opentripplanner/standalone/config/routerconfig/ClientMetricsConfig.java‎

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package org.opentripplanner.standalone.config.routerconfig;
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import java.util.Set;
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/**
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* Configuration for HTTP client request metrics.
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*
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* @param enabled whether client metrics are enabled
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* @param clientHeader the HTTP header name used to identify the client
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* @param knownClients the set of known client names to track individually
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*/
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public record ClientMetricsConfig(boolean enabled, String clientHeader, Set<String> knownClients) {
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public static final String DEFAULT_CLIENT_HEADER = "x-client-name";
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public static final ClientMetricsConfig DISABLED = new ClientMetricsConfig(
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false,
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DEFAULT_CLIENT_HEADER,
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Set.of()
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);
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public ClientMetricsConfig {
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knownClients = Set.copyOf(knownClients);
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}
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}

‎application/src/main/java/org/opentripplanner/standalone/config/routerconfig/ServerConfig.java‎

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@@ -6,6 +6,7 @@
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import java.time.Duration;
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import java.util.List;
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import java.util.Set;
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import org.opentripplanner.apis.support.graphql.injectdoc.ApiDocumentationProfile;
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import org.opentripplanner.framework.application.OtpAppException;
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import org.opentripplanner.standalone.config.framework.json.NodeAdapter;
@@ -17,6 +18,7 @@ public class ServerConfig implements OTPWebApplicationParameters {
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private final Duration apiProcessingTimeout;
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private final List<RequestTraceParameter> traceParameters;
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private final ApiDocumentationProfile apiDocumentationProfile;
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private final ClientMetricsConfig clientMetrics;
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public ServerConfig(String parameterName, NodeAdapter root) {
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NodeAdapter c = root
@@ -106,6 +108,50 @@ messages across multiple (micro-)services from the same user. This is done by se
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.asBoolean(false)
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)
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);
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var clientMetricsNode = c
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.of("clientMetrics")
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.since(V2_7)
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.summary("Configuration for HTTP client request metrics.")
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.description(
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"""
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When enabled, records response time metrics per client. The client is identified by a
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configurable HTTP header (`clientHeader`). Only clients in the `knownClients` list are
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tracked individually; unknown clients are grouped under "other" to prevent metric
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cardinality explosion. Requires the ActuatorAPI feature to be enabled.
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"""
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)
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.asObject();
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boolean clientMetricsEnabled = clientMetricsNode
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.of("enabled")
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.since(V2_7)
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.summary("Enable client request metrics.")
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.asBoolean(false);
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String clientHeader = clientMetricsNode
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.of("clientHeader")
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.since(V2_7)
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.summary("HTTP header name used to identify the client.")
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.asString(ClientMetricsConfig.DEFAULT_CLIENT_HEADER);
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Set<String> knownClients = Set.copyOf(
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clientMetricsNode
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.of("knownClients")
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.since(V2_7)
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.summary("List of known client names to track individually.")
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.description(
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"""
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Clients not in this list will be grouped under "other". This prevents high cardinality
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metrics when unknown clients send requests.
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"""
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)
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.asStringList(List.of())
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);
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this.clientMetrics = clientMetricsEnabled
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? new ClientMetricsConfig(true, clientHeader, knownClients)
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: ClientMetricsConfig.DISABLED;
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}
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public Duration apiProcessingTimeout() {
@@ -121,6 +167,11 @@ public ApiDocumentationProfile apiDocumentationProfile() {
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return apiDocumentationProfile;
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}
123169

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@Override
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public ClientMetricsConfig clientMetrics() {
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return clientMetrics;
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}
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public void validate(Duration streetRoutingTimeout) {
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if (
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!apiProcessingTimeout.isNegative() &&

‎application/src/main/java/org/opentripplanner/standalone/server/ClientRequestMetricsFilter.java‎

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package org.opentripplanner.standalone.server;
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import io.micrometer.core.instrument.MeterRegistry;
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import io.micrometer.core.instrument.Metrics;
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import io.micrometer.core.instrument.Timer;
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import jakarta.ws.rs.container.ContainerRequestContext;
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import jakarta.ws.rs.container.ContainerRequestFilter;
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import jakarta.ws.rs.container.ContainerResponseContext;
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import jakarta.ws.rs.container.ContainerResponseFilter;
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import java.time.Duration;
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import java.util.Locale;
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import java.util.Set;
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import java.util.concurrent.ConcurrentHashMap;
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import java.util.concurrent.TimeUnit;
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import java.util.stream.Collectors;
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/**
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* A Jersey filter that records HTTP request response times with client identification.
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* <p>
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* The client is identified by a configurable HTTP header. Only known clients
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* (configured via {@code server.clientMetrics.knownClients}) are tracked individually;
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* unknown or missing client names are grouped under the "other" tag to prevent cardinality explosion.
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* <p>
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* The metric {@code http.client.requests} is recorded as a Timer with percentile histograms,
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* allowing analysis of response time distribution per client.
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*/
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public class ClientRequestMetricsFilter implements ContainerRequestFilter, ContainerResponseFilter {
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static final String METRIC_NAME = "http_server_requests";
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private static final String START_TIME_PROPERTY = "metrics.startTime";
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private static final String OTHER_CLIENT = "other";
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private static final ClientRequestMetricsFilter DISABLED = new ClientRequestMetricsFilter();
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private final String clientHeader;
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private final Set<String> knownClients;
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private final MeterRegistry registry;
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private final boolean enabled;
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private final ConcurrentHashMap<TimerKey, Timer> timerCache;
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private record TimerKey(String client, String uri) {}
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/**
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* Creates a filter for recording client request metrics.
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*
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* @param clientHeader the HTTP header name used to identify the client
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* @param knownClients the set of known client names to track individually (case-insensitive)
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* @param registry the meter registry to record metrics to
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*/
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public ClientRequestMetricsFilter(
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String clientHeader,
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Set<String> knownClients,
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MeterRegistry registry
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) {
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this.clientHeader = clientHeader;
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this.knownClients = knownClients
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.stream()
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.map(s -> s.toLowerCase(Locale.ROOT))
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.collect(Collectors.toUnmodifiableSet());
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this.registry = registry;
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this.enabled = true;
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this.timerCache = new ConcurrentHashMap<>();
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}
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/**
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* Creates a filter using the global meter registry.
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*
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* @param clientHeader the HTTP header name used to identify the client
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* @param knownClients the set of known client names to track individually
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*/
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public ClientRequestMetricsFilter(String clientHeader, Set<String> knownClients) {
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this(clientHeader, knownClients, Metrics.globalRegistry);
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}
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/**
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* Private constructor for disabled filter.
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*/
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private ClientRequestMetricsFilter() {
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this.clientHeader = null;
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this.knownClients = Set.of();
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this.registry = null;
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this.enabled = false;
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this.timerCache = null;
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}
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/**
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* Returns a disabled filter that does nothing.
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*/
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public static ClientRequestMetricsFilter disabled() {
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return DISABLED;
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}
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@Override
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public void filter(ContainerRequestContext requestContext) {
95+
if (enabled) {
96+
requestContext.setProperty(START_TIME_PROPERTY, System.nanoTime());
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}
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}
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@Override
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public void filter(
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ContainerRequestContext requestContext,
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ContainerResponseContext responseContext
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) {
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if (!enabled) {
106+
return;
107+
}
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Long startTime = (Long) requestContext.getProperty(START_TIME_PROPERTY);
110+
if (startTime == null) {
111+
return;
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}
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String clientName = requestContext.getHeaderString(clientHeader);
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String clientTag = resolveClientTag(clientName);
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String uri = requestContext.getUriInfo().getRequestUri().getPath();
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long duration = System.nanoTime() - startTime;
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Timer timer = getTimer(clientTag, uri);
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timer.record(duration, TimeUnit.NANOSECONDS);
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}
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private Timer getTimer(String clientTag, String uri) {
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return timerCache.computeIfAbsent(new TimerKey(clientTag, uri), key ->
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Timer.builder(METRIC_NAME)
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.description("HTTP request response time by client")
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.tag("client", key.client())
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.tag("uri", key.uri())
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.publishPercentileHistogram()
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.minimumExpectedValue(Duration.ofMillis(100))
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.maximumExpectedValue(Duration.ofMillis(1000))
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.register(registry)
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);
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}
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private String resolveClientTag(String clientName) {
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if (clientName != null) {
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String lowercaseName = clientName.toLowerCase(Locale.ROOT);
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if (knownClients.contains(lowercaseName)) {
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return lowercaseName;
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}
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}
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return OTHER_CLIENT;
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}
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}

‎application/src/main/java/org/opentripplanner/standalone/server/OTPWebApplication.java‎

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@@ -20,6 +20,7 @@
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import org.opentripplanner.apis.APIEndpoints;
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import org.opentripplanner.framework.application.OTPFeature;
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import org.opentripplanner.standalone.api.OtpServerRequestContext;
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import org.opentripplanner.standalone.config.routerconfig.ClientMetricsConfig;
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import org.slf4j.bridge.SLF4JBridgeHandler;
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2526
/**
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private final Supplier<OtpServerRequestContext> contextProvider;
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3839
private final List<Class<? extends ContainerResponseFilter>> customFilters;
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private final ClientMetricsConfig clientMetricsConfig;
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4042
static {
4143
// Remove existing handlers attached to the j.u.l root logger
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) {
5254
this.contextProvider = contextProvider;
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this.customFilters = createCustomFilters(parameters.traceParameters());
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this.clientMetricsConfig = parameters.clientMetrics();
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}
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/**
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108111

109112
if (OTPFeature.ActuatorAPI.isOn()) {
110113
singletons.add(getBoundPrometheusRegistry());
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115+
// Add client request metrics filter if enabled
116+
if (clientMetricsConfig.enabled()) {
117+
singletons.add(
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new ClientRequestMetricsFilter(
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clientMetricsConfig.clientHeader(),
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clientMetricsConfig.knownClients()
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)
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);
123+
}
111124
}
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113126
return singletons;

‎application/src/main/java/org/opentripplanner/standalone/server/OTPWebApplicationParameters.java‎

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package org.opentripplanner.standalone.server;
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33
import java.util.List;
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import org.opentripplanner.standalone.config.routerconfig.ClientMetricsConfig;
45

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/**
67
* Parameters used to configure the {@link OTPWebApplication}.
@@ -14,4 +15,11 @@ public interface OTPWebApplicationParameters {
1415
default boolean requestTraceLoggingEnabled() {
1516
return traceParameters().stream().anyMatch(RequestTraceParameter::hasLogKey);
1617
}
18+
19+
/**
20+
* Configuration for client request metrics.
21+
*/
22+
default ClientMetricsConfig clientMetrics() {
23+
return ClientMetricsConfig.DISABLED;
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}
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}

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