diff --git a/Gopkg.lock b/Gopkg.lock
index 9eb3b1d3..144bbb82 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -147,14 +147,14 @@
 
 [[projects]]
   branch = "master"
-  digest = "1:921c8888ac7bf7240bc5473d029201b3eb19f9592c7647c4c29f96b6c901b1bb"
+  digest = "1:f27efa11fb1aec3e502e2ed95d9a1211a93f8a791b7da0a06fdade0d98de5008"
   name = "github.com/knative/test-infra"
   packages = [
     "scripts",
     "tools/dep-collector",
   ]
   pruneopts = "UT"
-  revision = "582b6fbee8ae00260baf916b0f9db2aa5f3483d9"
+  revision = "75f6ca1c4dc3b3ae5dc1a1a433753957a9340e83"
 
 [[projects]]
   digest = "1:2f42fa12d6911c7b7659738758631bec870b7e9b4c6be5444f963cdcfccc191f"
diff --git a/vendor/github.com/knative/test-infra/scripts/README.md b/vendor/github.com/knative/test-infra/scripts/README.md
index 07398fb7..f7841871 100644
--- a/vendor/github.com/knative/test-infra/scripts/README.md
+++ b/vendor/github.com/knative/test-infra/scripts/README.md
@@ -108,8 +108,10 @@ This is a helper script for Knative E2E test scripts. To use it:
    if the default values don't fit your needs:
 
    - `E2E_CLUSTER_REGION`: Cluster region, defaults to `us-central1`.
+   - `E2E_CLUSTER_BACKUP_REGIONS`: Space-separated list of regions to retry test cluster creation in case of stockout. Defaults to `us-west1 us-east1`.
    - `E2E_CLUSTER_ZONE`: Cluster zone (e.g., `a`), defaults to none (i.e. use a regional
      cluster).
+   - `E2E_CLUSTER_BACKUP_ZONES`: Space-separated list of zones to retry test cluster creation in case of stockout. If defined, `E2E_CLUSTER_BACKUP_REGIONS` will be ignored thus it defaults to none.
    - `E2E_CLUSTER_MACHINE`: Cluster node machine type, defaults to `n1-standard-4}`.
    - `E2E_MIN_CLUSTER_NODES`: Minimum number of nodes in the cluster when autoscaling,
      defaults to 1.
@@ -153,8 +155,9 @@ This is a helper script for Knative E2E test scripts. To use it:
 1. Write logic for the end-to-end tests. Run all go tests using `go_test_e2e()`
    (or `report_go_test()` if you need a more fine-grained control) and call
    `fail_test()` or `success()` if any of them failed. The environment variable
-   `KO_DOCKER_REPO` will be set according to the test cluster. You can also use
-   the following boolean (0 is false, 1 is true) environment variables for the logic:
+   `KO_DOCKER_REPO` and `E2E_PROJECT_ID` will be set according to the test cluster.
+   You can also use the following boolean (0 is false, 1 is true) environment
+   variables for the logic:
 
    - `EMIT_METRICS`: true if `--emit-metrics` was passed.
 
@@ -169,6 +172,9 @@ This is a helper script for Knative E2E test scripts. To use it:
    will immediately start the tests against the cluster currently configured for
    `kubectl`.
 
+1. By default Istio is installed on the cluster via Addon, using `--skip-istio` if
+   you choose not to have it preinstalled.
+
 1. You can force running the tests against a specific GKE cluster version by using
    the `--cluster-version` flag and passing a full version as the flag value.
 
diff --git a/vendor/github.com/knative/test-infra/scripts/e2e-tests.sh b/vendor/github.com/knative/test-infra/scripts/e2e-tests.sh
index c2328e7b..5c515594 100755
--- a/vendor/github.com/knative/test-infra/scripts/e2e-tests.sh
+++ b/vendor/github.com/knative/test-infra/scripts/e2e-tests.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# Copyright 2018 The Knative Authors
+# Copyright 2019 The Knative Authors
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -38,9 +38,15 @@ function build_resource_name() {
 # Test cluster parameters
 
 # Configurable parameters
-readonly E2E_CLUSTER_REGION=${E2E_CLUSTER_REGION:-us-central1}
+# export E2E_CLUSTER_REGION and E2E_CLUSTER_ZONE as they're used in the cluster setup subprocess
+export E2E_CLUSTER_REGION=${E2E_CLUSTER_REGION:-us-central1}
 # By default we use regional clusters.
-readonly E2E_CLUSTER_ZONE=${E2E_CLUSTER_ZONE:-}
+export E2E_CLUSTER_ZONE=${E2E_CLUSTER_ZONE:-}
+
+# Default backup regions in case of stockouts; by default we don't fall back to a different zone in the same region
+readonly E2E_CLUSTER_BACKUP_REGIONS=${E2E_CLUSTER_BACKUP_REGIONS:-us-west1 us-east1}
+readonly E2E_CLUSTER_BACKUP_ZONES=${E2E_CLUSTER_BACKUP_ZONES:-}
+
 readonly E2E_CLUSTER_MACHINE=${E2E_CLUSTER_MACHINE:-n1-standard-4}
 readonly E2E_GKE_ENVIRONMENT=${E2E_GKE_ENVIRONMENT:-prod}
 readonly E2E_GKE_COMMAND_GROUP=${E2E_GKE_COMMAND_GROUP:-beta}
@@ -61,6 +67,8 @@ IS_BOSKOS=0
 
 # Tear down the test resources.
 function teardown_test_resources() {
+  # On boskos, save time and don't teardown as the cluster will be destroyed anyway.
+  (( IS_BOSKOS )) && return
   header "Tearing down test environment"
   function_exists test_teardown && test_teardown
   (( ! SKIP_KNATIVE_SETUP )) && function_exists knative_teardown && knative_teardown
@@ -107,8 +115,7 @@ function save_metadata() {
     geo_key="Zone"
     geo_value="${E2E_CLUSTER_REGION}-${E2E_CLUSTER_ZONE}"
   fi
-  local gcloud_project="$(gcloud config get-value project)"
-  local cluster_version="$(gcloud container clusters list --project=${gcloud_project} --format='value(currentMasterVersion)')"
+  local cluster_version="$(gcloud container clusters list --project=${E2E_PROJECT_ID} --format='value(currentMasterVersion)')"
   cat << EOF > ${ARTIFACTS}/metadata.json
 {
   "E2E:${geo_key}": "${geo_value}",
@@ -124,6 +131,7 @@ EOF
 # See https://github.com/knative/serving/issues/959 for details.
 # TODO(adrcunha): Remove once the leak issue is resolved.
 function delete_leaked_network_resources() {
+  # On boskos, don't bother with leaks as the janitor will delete everything in the project.
   (( IS_BOSKOS )) && return
   # Ensure we're using the GCP project used by kubetest
   local gcloud_project="$(gcloud config get-value project)"
@@ -154,20 +162,15 @@ function create_test_cluster() {
     cluster_setup || fail_test "cluster setup failed"
   fi
 
-  header "Creating test cluster"
-
   echo "Cluster will have a minimum of ${E2E_MIN_CLUSTER_NODES} and a maximum of ${E2E_MAX_CLUSTER_NODES} nodes."
 
   # Smallest cluster required to run the end-to-end-tests
-  local geoflag="--gcp-region=${E2E_CLUSTER_REGION}"
-  [[ -n "${E2E_CLUSTER_ZONE}" ]] && geoflag="--gcp-zone=${E2E_CLUSTER_REGION}-${E2E_CLUSTER_ZONE}"
   local CLUSTER_CREATION_ARGS=(
-    --gke-create-command="container clusters create --quiet --enable-autoscaling --min-nodes=${E2E_MIN_CLUSTER_NODES} --max-nodes=${E2E_MAX_CLUSTER_NODES} --scopes=cloud-platform --enable-basic-auth --no-issue-client-certificate ${EXTRA_CLUSTER_CREATION_FLAGS[@]}"
+    --gke-create-command="container clusters create --quiet --enable-autoscaling --min-nodes=${E2E_MIN_CLUSTER_NODES} --max-nodes=${E2E_MAX_CLUSTER_NODES} --scopes=cloud-platform --enable-basic-auth --no-issue-client-certificate ${GKE_ADDONS} ${EXTRA_CLUSTER_CREATION_FLAGS[@]}"
     --gke-shape={\"default\":{\"Nodes\":${E2E_MIN_CLUSTER_NODES}\,\"MachineType\":\"${E2E_CLUSTER_MACHINE}\"}}
     --provider=gke
     --deployment=gke
     --cluster="${E2E_CLUSTER_NAME}"
-    ${geoflag}
     --gcp-network="${E2E_NETWORK_NAME}"
     --gke-environment="${E2E_GKE_ENVIRONMENT}"
     --gke-command-group="${E2E_GKE_COMMAND_GROUP}"
@@ -198,11 +201,7 @@ function create_test_cluster() {
   local extra_flags=()
   # If using boskos, save time and let it tear down the cluster
   (( ! IS_BOSKOS )) && extra_flags+=(--down)
-  # Don't fail test for kubetest, as it might incorrectly report test failure
-  # if teardown fails (for details, see success() below)
-  set +o errexit
-  run_go_tool k8s.io/test-infra/kubetest \
-    kubetest "${CLUSTER_CREATION_ARGS[@]}" \
+  create_test_cluster_with_retries "${CLUSTER_CREATION_ARGS[@]}" \
     --up \
     --extract "${E2E_CLUSTER_VERSION}" \
     --gcp-node-image "${SERVING_GKE_IMAGE}" \
@@ -215,12 +214,55 @@ function create_test_cluster() {
   set +o errexit
   function_exists cluster_teardown && cluster_teardown
   delete_leaked_network_resources
-  local result="$(cat ${TEST_RESULT_FILE})"
+  local result=$(get_test_return_code)
   echo "Artifacts were written to ${ARTIFACTS}"
   echo "Test result code is ${result}"
   exit ${result}
 }
 
+# Retry backup regions/zones if cluster creations failed due to stockout.
+# Parameters: $1..$n - any kubetest flags other than geo flag.
+function create_test_cluster_with_retries() {
+  local cluster_creation_log=/tmp/${E2E_BASE_NAME}-cluster_creation-log
+  # zone_not_provided is a placeholder for e2e_cluster_zone to make for loop below work
+  local zone_not_provided="zone_not_provided"
+
+  local e2e_cluster_regions=(${E2E_CLUSTER_REGION})
+  local e2e_cluster_zones=(${E2E_CLUSTER_ZONE})
+
+  if [[ -n "${E2E_CLUSTER_BACKUP_ZONES}" ]]; then
+    e2e_cluster_zones+=(${E2E_CLUSTER_BACKUP_ZONES})
+  elif [[ -n "${E2E_CLUSTER_BACKUP_REGIONS}" ]]; then
+    e2e_cluster_regions+=(${E2E_CLUSTER_BACKUP_REGIONS})
+    e2e_cluster_zones=(${zone_not_provided})
+  else
+    echo "No backup region/zone set, cluster creation will fail in case of stockout"
+  fi
+
+  for e2e_cluster_region in "${e2e_cluster_regions[@]}"; do
+    for e2e_cluster_zone in "${e2e_cluster_zones[@]}"; do
+      E2E_CLUSTER_REGION=${e2e_cluster_region}
+      E2E_CLUSTER_ZONE=${e2e_cluster_zone}
+      [[ "${E2E_CLUSTER_ZONE}" == "${zone_not_provided}" ]] && E2E_CLUSTER_ZONE=""
+
+      local geoflag="--gcp-region=${E2E_CLUSTER_REGION}"
+      [[ -n "${E2E_CLUSTER_ZONE}" ]] && geoflag="--gcp-zone=${E2E_CLUSTER_REGION}-${E2E_CLUSTER_ZONE}"
+
+      header "Creating test cluster in $E2E_CLUSTER_REGION $E2E_CLUSTER_ZONE"
+      # Don't fail test for kubetest, as it might incorrectly report test failure
+      # if teardown fails (for details, see success() below)
+      set +o errexit
+      { run_go_tool k8s.io/test-infra/kubetest \
+        kubetest "$@" ${geoflag}; } 2>&1 | tee ${cluster_creation_log}
+
+      # Exit if test succeeded
+      [[ "$(get_test_return_code)" == "0" ]] && return
+      # If test failed not because of cluster creation stockout, return
+      [[ -z "$(grep -Eio 'does not have enough resources available to fulfill the request' ${cluster_creation_log})" ]] && return
+    done
+  done
+}
+
 # Setup the test cluster for running the tests.
 function setup_test_cluster() {
   # Fail fast during setup.
@@ -229,6 +271,11 @@ function setup_test_cluster() {
 
   header "Setting up test cluster"
 
+  # Set the actual project the test cluster resides in
+  # It will be a project assigned by Boskos if test is running on Prow, 
+  # otherwise will be ${GCP_PROJECT} set up by user.
+  readonly export E2E_PROJECT_ID="$(gcloud config get-value project)"
+
   # Save some metadata about cluster creation for using in prow and testgrid
   save_metadata
 
@@ -240,9 +287,10 @@ function setup_test_cluster() {
   if [[ -z "$(kubectl get clusterrolebinding cluster-admin-binding 2> /dev/null)" ]]; then
     acquire_cluster_admin_role ${k8s_user} ${E2E_CLUSTER_NAME} ${E2E_CLUSTER_REGION} ${E2E_CLUSTER_ZONE}
     kubectl config set-context ${k8s_cluster} --namespace=default
-    export KO_DOCKER_REPO=gcr.io/$(gcloud config get-value project)/${E2E_BASE_NAME}-e2e-img
+    export KO_DOCKER_REPO=gcr.io/${E2E_PROJECT_ID}/${E2E_BASE_NAME}-e2e-img
   fi
 
+  echo "- Project is ${E2E_PROJECT_ID}"
   echo "- Cluster is ${k8s_cluster}"
   echo "- User is ${k8s_user}"
   echo "- Docker is ${KO_DOCKER_REPO}"
@@ -263,6 +311,12 @@ function setup_test_cluster() {
   fi
 }
 
+# Gets the exit of the test script.
+# For more details, see set_test_return_code().
+function get_test_return_code() {
+  echo $(cat ${TEST_RESULT_FILE})
+}
+
 # Set the return code that the test script will return.
 # Parameters: $1 - return code (0-255)
 function set_test_return_code() {
@@ -295,9 +349,11 @@ function fail_test() {
 RUN_TESTS=0
 EMIT_METRICS=0
 SKIP_KNATIVE_SETUP=0
+SKIP_ISTIO=0
 GCP_PROJECT=""
 E2E_SCRIPT=""
 E2E_CLUSTER_VERSION=""
+GKE_ADDONS=""
 EXTRA_CLUSTER_CREATION_FLAGS=()
 EXTRA_KUBETEST_FLAGS=()
 E2E_SCRIPT_CUSTOM_FLAGS=()
@@ -329,6 +385,7 @@ function initialize() {
       --run-tests) RUN_TESTS=1 ;;
       --emit-metrics) EMIT_METRICS=1 ;;
       --skip-knative-setup) SKIP_KNATIVE_SETUP=1 ;;
+      --skip-istio) SKIP_ISTIO=1 ;;
       *)
         [[ $# -ge 2 ]] || abort "missing parameter after $1"
         shift
@@ -358,6 +415,8 @@ function initialize() {
   is_protected_gcr ${KO_DOCKER_REPO} && \
     abort "\$KO_DOCKER_REPO set to ${KO_DOCKER_REPO}, which is forbidden"
 
+  (( SKIP_ISTIO )) || GKE_ADDONS="--addons=Istio"
+
   readonly RUN_TESTS
   readonly EMIT_METRICS
   readonly GCP_PROJECT
@@ -365,6 +424,7 @@ function initialize() {
   readonly EXTRA_CLUSTER_CREATION_FLAGS
   readonly EXTRA_KUBETEST_FLAGS
   readonly SKIP_KNATIVE_SETUP
+  readonly GKE_ADDONS
 
   if (( ! RUN_TESTS )); then
     create_test_cluster
diff --git a/vendor/github.com/knative/test-infra/scripts/library.sh b/vendor/github.com/knative/test-infra/scripts/library.sh
index 89a93c91..b3216758 100755
--- a/vendor/github.com/knative/test-infra/scripts/library.sh
+++ b/vendor/github.com/knative/test-infra/scripts/library.sh
@@ -146,22 +146,23 @@ function wait_until_pods_running() {
   return 1
 }
 
-# Waits until all batch job pods are running in the given namespace.
+# Waits until all batch jobs complete in the given namespace.
 # Parameters: $1 - namespace.
 function wait_until_batch_job_complete() {
-  echo -n "Waiting until all batch job pods in namespace $1 run to completion."
+  echo -n "Waiting until all batch jobs in namespace $1 run to completion."
   for i in {1..150}; do  # timeout after 5 minutes
-    local pods="$(kubectl get pods --selector=job-name --no-headers -n $1 2>/dev/null | grep -v '^[[:space:]]*$')"
-    # All pods must be complete
-    local not_complete=$(echo "${pods}" | grep -v Completed | wc -l)
+    local jobs=$(kubectl get jobs -n $1 --no-headers \
+                 -ocustom-columns='n:{.metadata.name},c:{.spec.completions},s:{.status.succeeded}')
+    # All jobs must be complete
+    local not_complete=$(echo "${jobs}" | awk '{if ($2!=$3) print $0}' | wc -l)
     if [[ ${not_complete} -eq 0 ]]; then
-      echo -e "\nAll pods are complete:\n${pods}"
+      echo -e "\nAll jobs are complete:\n${jobs}"
       return 0
     fi
     echo -n "."
     sleep 2
   done
-  echo -e "\n\nERROR: timeout waiting for pods to complete\n${pods}"
+  echo -e "\n\nERROR: timeout waiting for jobs to complete\n${jobs}"
   return 1
 }
 
@@ -320,14 +321,6 @@ function report_go_test() {
 # Install the latest stable Knative/serving in the current cluster.
 function start_latest_knative_serving() {
   header "Starting Knative Serving"
-  subheader "Installing Istio"
-  echo "Running Istio CRD from ${KNATIVE_ISTIO_CRD_YAML}"
-  kubectl apply -f ${KNATIVE_ISTIO_CRD_YAML} || return 1
-  wait_until_batch_job_complete istio-system || return 1
-  echo "Installing Istio from ${KNATIVE_ISTIO_YAML}"
-  kubectl apply -f ${KNATIVE_ISTIO_YAML} || return 1
-  wait_until_pods_running istio-system || return 1
-  kubectl label namespace default istio-injection=enabled || return 1
   subheader "Installing Knative Serving"
   echo "Installing Serving from ${KNATIVE_SERVING_RELEASE}"
   kubectl apply -f ${KNATIVE_SERVING_RELEASE} || return 1
diff --git a/vendor/github.com/knative/test-infra/scripts/presubmit-tests.sh b/vendor/github.com/knative/test-infra/scripts/presubmit-tests.sh
index b10a8515..3f15cf3a 100755
--- a/vendor/github.com/knative/test-infra/scripts/presubmit-tests.sh
+++ b/vendor/github.com/knative/test-infra/scripts/presubmit-tests.sh
@@ -43,7 +43,7 @@ IS_DOCUMENTATION_PR=0
 # Returns true if PR only contains the given file regexes.
 # Parameters: $1 - file regexes, space separated.
 function pr_only_contains() {
-  [[ -z "$(echo "${CHANGED_FILES}" | grep -v \(${1// /\\|}\)$))" ]]
+  [[ -z "$(echo "${CHANGED_FILES}" | grep -v "\(${1// /\\|}\)$")" ]]
 }
 
 # List changed files in the current PR.