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Add http metrics http_request_duration_seconds and http_requests_total
.) http_request_duration_seconds (histogram) -> Labels (path,method) .) http_requests_total (counter) -> Labels (path,method,status) Where path is the REST path of the ressource, method is the HTTP method (GET,PUT..) and status is the HTTP response code (2xx, 3xx ...)
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lines changed

3 files changed

+195
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‎src/main/java/com/gitblit/guice/WebModule.java

+11-2
Original file line numberDiff line numberDiff line change
@@ -30,6 +30,7 @@
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import com.gitblit.servlet.GitFilter;
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import com.gitblit.servlet.GitServlet;
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import com.gitblit.servlet.LogoServlet;
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import com.gitblit.servlet.MetricsFilter;
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import com.gitblit.servlet.PagesFilter;
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import com.gitblit.servlet.PagesServlet;
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import com.gitblit.servlet.ProxyFilter;
@@ -43,7 +44,9 @@
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import com.gitblit.servlet.SyndicationFilter;
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import com.gitblit.servlet.SyndicationServlet;
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import com.gitblit.wicket.GitblitWicketFilter;
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import com.google.common.base.Joiner;
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import com.google.common.collect.ImmutableMap;
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import com.google.inject.Scopes;
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import com.google.inject.servlet.ServletModule;
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import io.prometheus.client.exporter.MetricsServlet;
@@ -84,6 +87,7 @@ protected void configureServlets() {
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// Prometheus
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bind(MetricsServlet.class).in(Scopes.SINGLETON);
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bind(MetricsFilter.class).in(Scopes.SINGLETON);
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serve("/prometheus").with(MetricsServlet.class);
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DefaultExports.initialize();
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@@ -99,8 +103,13 @@ protected void configureServlets() {
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serve(fuzzy("/com/")).with(AccessDeniedServlet.class);
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// global filters
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filter(ALL).through(ProxyFilter.class);
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filter(ALL).through(EnforceAuthenticationFilter.class);
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filter(ALL).through(MetricsFilter.class,
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ImmutableMap.of(
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MetricsFilter.PARAM_DURATION_HIST_BUCKET_CONFIG, "0.005,0.01,0.025,0.05,0.075,0.1,0.25,0.5,0.75,1,2.5,5,7.5,10",
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MetricsFilter.PARAM_PATH_MAX_DEPTH, "16"
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));
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filter(ALL).through(ProxyFilter.class);
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filter(ALL).through(EnforceAuthenticationFilter.class);
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// security filters
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filter(fuzzy(Constants.R_PATH), fuzzy(Constants.GIT_PATH)).through(GitFilter.class);

‎src/main/java/com/gitblit/servlet/MetricsFilter.java

+134
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@@ -0,0 +1,134 @@
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package com.gitblit.servlet;
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import io.prometheus.client.Counter;
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import io.prometheus.client.Histogram;
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import javax.servlet.*;
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import javax.servlet.http.HttpServletRequest;
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import javax.servlet.http.HttpServletResponse;
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import java.io.IOException;
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/**
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*/
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public class MetricsFilter implements Filter {
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public static final String PARAM_PATH_MAX_DEPTH = "max-path-depth";
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public static final String PARAM_DURATION_HIST_BUCKET_CONFIG = "request-duration-histogram-buckets";
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private Histogram httpRequestDuration = null;
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private Counter requests = null;
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// Package-level for testing purposes.
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int pathDepth = 1;
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private double[] buckets = null;
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public MetricsFilter() {
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}
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public MetricsFilter(
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Integer maxPathDepth,
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double[] buckets
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) throws ServletException {
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this.buckets = buckets;
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if (maxPathDepth != null) {
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this.pathDepth = maxPathDepth;
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}
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this.init(null);
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}
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private boolean isEmpty(String s) {
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return s == null || s.length() == 0;
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}
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@Override
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public void init(FilterConfig filterConfig) throws ServletException {
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Histogram.Builder httpRequestDurationBuilder = Histogram.build()
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.name("http_request_duration_seconds")
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.labelNames("path", "method")
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.help("The time taken fulfilling servlet requests");
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Counter.Builder requestsBuilder = Counter.build()
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.name("http_requests_total")
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.help("Total requests.")
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.labelNames("path", "method", "status");
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if (filterConfig == null && isEmpty("http_request_duration")) {
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throw new ServletException("No configuration object provided, and no metricName passed via constructor");
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}
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if (filterConfig != null) {
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// Allow overriding of the path "depth" to track
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if (!isEmpty(filterConfig.getInitParameter(PARAM_PATH_MAX_DEPTH))) {
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pathDepth = Integer.valueOf(filterConfig.getInitParameter(PARAM_PATH_MAX_DEPTH));
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}
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// Allow users to override the default bucket configuration
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if (!isEmpty(filterConfig.getInitParameter(PARAM_DURATION_HIST_BUCKET_CONFIG))) {
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String[] bucketParams = filterConfig.getInitParameter(PARAM_DURATION_HIST_BUCKET_CONFIG).split(",");
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buckets = new double[bucketParams.length];
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for (int i = 0; i < bucketParams.length; i++) {
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buckets[i] = Double.parseDouble(bucketParams[i]);
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}
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}
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}
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requests = requestsBuilder.register();
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if (buckets != null) {
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httpRequestDurationBuilder = httpRequestDurationBuilder.buckets(buckets);
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}
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httpRequestDuration = httpRequestDurationBuilder.register();
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}
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@Override
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public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
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if (!(servletRequest instanceof HttpServletRequest)) {
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filterChain.doFilter(servletRequest, servletResponse);
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return;
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}
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HttpServletRequest request = (HttpServletRequest) servletRequest;
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HttpServletResponse response = (HttpServletResponse) servletResponse;
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String path = request.getRequestURI();
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String normalizedPath = extractPathFrom(path, pathDepth);
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Histogram.Timer timer = httpRequestDuration
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.labels(normalizedPath, request.getMethod())
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.startTimer();
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try {
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filterChain.doFilter(servletRequest, servletResponse);
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requests.labels(normalizedPath, request.getMethod(), String.valueOf(response.getStatus())).inc();
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} finally {
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timer.observeDuration();
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}
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}
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public String extractPathFrom(String requestUri, int maxPathDepth) {
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if (maxPathDepth < 0 || requestUri == null) {
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throw new IllegalArgumentException("Path depth has to >= 0");
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}
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int count = 0;
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int pathPosition = -1;
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do {
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int lastPathPosition = pathPosition;
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pathPosition = requestUri.indexOf("/", pathPosition + 1);
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if (count > maxPathDepth || pathPosition < 0) {
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return requestUri.substring(0, lastPathPosition + 1);
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}
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count++;
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} while (count <= maxPathDepth);
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return requestUri.substring(0, pathPosition + 1);
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}
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@Override
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public void destroy() {
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}
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}
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‎src/test/java/com/gitblit/tests/MetricsFilterTest.java

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@@ -0,0 +1,50 @@
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package com.gitblit.tests;
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import com.gitblit.servlet.MetricsFilter;
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import org.junit.Test;
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import static org.hamcrest.CoreMatchers.*;
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import static org.junit.Assert.*;
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public class MetricsFilterTest {
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@Test
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public void alwaysExtractRootPathForZeroPathLength() {
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MetricsFilter metricsFilter = new MetricsFilter();
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String path = metricsFilter.extractPathFrom("/index.html", 0);
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assertThat(path, equalTo("/"));
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}
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@Test
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public void useAlwaysRootPathForLongPathLength() {
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MetricsFilter metricsFilter = new MetricsFilter();
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String path = metricsFilter.extractPathFrom("/index.html", 1);
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assertThat(path, equalTo("/"));
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}
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@Test
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public void pathDepthOneuseAlwaysRootPathForZeroPathLength() {
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MetricsFilter metricsFilter = new MetricsFilter();
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String path = metricsFilter.extractPathFrom("/test/index.html", 1);
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assertThat(path, equalTo("/test/"));
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}
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@Test
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public void cutsPathsLongerThanPathDepth() {
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MetricsFilter metricsFilter = new MetricsFilter();
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String path = metricsFilter.extractPathFrom("/test/tralala/index.html", 1);
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assertThat(path, equalTo("/test/"));
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}
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@Test(expected = IllegalArgumentException.class)
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public void throwsExceptionForNegativePathDepth() {
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new MetricsFilter().extractPathFrom("/index.html", -1);
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}
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@Test(expected = IllegalArgumentException.class)
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public void throwsExceptionForNullRequestPath() {
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new MetricsFilter().extractPathFrom(null, 1);
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}
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}

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