--- title: Troubleshooting Guide description: Practical advice on practical problems with Istio weight: 40 aliases: - /troubleshooting.html - /troubleshooting/index.html force_inline_toc: true --- Oh no! You're having trouble? Below is a list of solutions to common problems. ## Route rules have no effect on my application If route rules are working perfectly for the [Bookinfo](/docs/guides/bookinfo/) sample, but similar version routing rules have no effect on your own application, it may be that your Kubernetes services need to be changed slightly. Kubernetes services must adhere to certain restrictions in order to take advantage of Istio's L7 routing features. Refer to the [sidecar injection documentation](/docs/setup/kubernetes/sidecar-injection/#pod-spec-requirements) for details. ## Verifying connectivity to Istio Pilot Verifying connectivity to Pilot is a useful troubleshooting step. Every proxy container in the service mesh should be able to communicate with Pilot. This can be accomplished in a few simple steps: 1. Get the name of the Istio Ingress pod: ```command $ INGRESS_POD_NAME=$(kubectl get po -n istio-system | grep ingress\- | awk '{print$1}') ``` 1. Exec into the Istio Ingress pod: ```command $ kubectl exec -it $INGRESS_POD_NAME -n istio-system /bin/bash ``` 1. Test connectivity to Pilot using cURL. The following example cURL's the v1 registration API using default Pilot configuration parameters and mTLS enabled: ```command $ curl -k --cert /etc/certs/cert-chain.pem --cacert /etc/certs/root-cert.pem --key /etc/certs/key.pem https://istio-pilot:15003/v1/registration ``` If mTLS is disabled: ```command $ curl http://istio-pilot:15003/v1/registration ``` You should receive a response listing the "service-key" and "hosts" for each service in the mesh. ## No traces appearing in Zipkin when running Istio locally on Mac Istio is installed and everything seems to be working except there are no traces showing up in Zipkin when there should be. This may be caused by a known [Docker issue](https://github.com/docker/for-mac/issues/1260) where the time inside containers may skew significantly from the time on the host machine. If this is the case, when you select a very long date range in Zipkin you will see the traces appearing as much as several days too early. You can also confirm this problem by comparing the date inside a docker container to outside: ```command $ docker run --entrypoint date gcr.io/istio-testing/ubuntu-16-04-slave:latest Sun Jun 11 11:44:18 UTC 2017 ``` ```command $ date -u Thu Jun 15 02:25:42 UTC 2017 ``` To fix the problem, you'll need to shutdown and then restart Docker before reinstalling Istio. ## Envoy won't connect to my HTTP/1.0 service Envoy requires HTTP/1.1 or HTTP/2 traffic for upstream services. For example, when using [NGINX](https://www.nginx.com/) for serving traffic behind Envoy, you will need to set the [proxy_http_version](https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_http_version) directive in your NGINX config to be "1.1", since the NGINX default is 1.0 Example config: ```plain upstream http_backend { server 127.0.0.1:8080; keepalive 16; } server { ... location /http/ { proxy_pass http://http_backend; proxy_http_version 1.1; proxy_set_header Connection ""; ... } } ``` ## No Grafana output when connecting from a local web client to Istio remotely hosted Validate the client and server date and time match. The time of the web client (e.g. Chrome) affects the output from Grafana. A simple solution to this problem is to verify a time synchronization service is running correctly within the Kubernetes cluster and the web client machine also is correctly using a time synchronization service. Some common time synchronization systems are NTP and Chrony. This is especially problematic is engineering labs with firewalls. In these scenarios, NTP may not be configured properly to point at the lab-based NTP services. ## Where are the metrics for my service? The expected flow of metrics is: 1. Envoy reports attributes to Mixer in batch (asynchronously from requests) 1. Mixer translates the attributes from Mixer into instances based on operator-provided configuration. 1. The instances are handed to Mixer adapters for processing and backend storage. 1. The backend storage systems record metrics data. The default installations of Mixer ship with a [Prometheus](https://prometheus.io/) adapter, as well as configuration for generating a basic set of metric values and sending them to the Prometheus adapter. The [Prometheus add-on](/docs/tasks/telemetry/querying-metrics/#about-the-prometheus-add-on) also supplies configuration for an instance of Prometheus to scrape Mixer for metrics. If you do not see the expected metrics in the Istio Dashboard and/or via Prometheus queries, there may be an issue at any of the steps in the flow listed above. Below is a set of instructions to troubleshoot each of those steps. ### Verify Mixer is receiving Report calls Mixer generates metrics for monitoring the behavior of Mixer itself. Check these metrics. 1. Establish a connection to the Mixer self-monitoring endpoint. In Kubernetes environments, execute the following command: ```command $ kubectl -n istio-system port-forward 9093 & ``` 1. Verify successful report calls. On the [Mixer self-monitoring endpoint](http://localhost:9093/metrics), search for `grpc_server_handled_total`. You should see something like: ```plain grpc_server_handled_total{grpc_code="OK",grpc_method="Report",grpc_service="istio.mixer.v1.Mixer",grpc_type="unary"} 68 ``` If you do not see any data for `grpc_server_handled_total` with a `grpc_method="Report"`, then Mixer is not being called by Envoy to report telemetry. In this case, ensure that the services have been properly integrated into the mesh (either by via [automatic](/docs/setup/kubernetes/sidecar-injection/#automatic-sidecar-injection) or [manual](/docs/setup/kubernetes/sidecar-injection/#manual-sidecar-injection) sidecar injection). ### Verify Mixer metrics configuration exists 1. Verify Mixer rules exist. In Kubernetes environments, issue the following command: ```command $ kubectl get rules --all-namespaces NAMESPACE NAME KIND istio-system promhttp rule.v1alpha2.config.istio.io istio-system promtcp rule.v1alpha2.config.istio.io istio-system stdio rule.v1alpha2.config.istio.io ``` If you do not see anything named `promhttp` or `promtcp`, then there is no Mixer configuration for sending metric instances to a Prometheus adapter. You will need to supply configuration for rules that connect Mixer metric instances to a Prometheus handler. 1. Verify Prometheus handler config exists. In Kubernetes environments, issue the following command: ```command $ kubectl get prometheuses.config.istio.io --all-namespaces NAMESPACE NAME KIND istio-system handler prometheus.v1alpha2.config.istio.io ``` If there are no prometheus handlers configured, you will need to reconfigure Mixer with the appropriate handler configuration. 1. Verify Mixer metric instances config exists. In Kubernetes environments, issue the following command: ```command $ kubectl get metrics.config.istio.io --all-namespaces NAMESPACE NAME KIND istio-system requestcount metric.v1alpha2.config.istio.io istio-system requestduration metric.v1alpha2.config.istio.io istio-system requestsize metric.v1alpha2.config.istio.io istio-system responsesize metric.v1alpha2.config.istio.io istio-system stackdriverrequestcount metric.v1alpha2.config.istio.io istio-system stackdriverrequestduration metric.v1alpha2.config.istio.io istio-system stackdriverrequestsize metric.v1alpha2.config.istio.io istio-system stackdriverresponsesize metric.v1alpha2.config.istio.io istio-system tcpbytereceived metric.v1alpha2.config.istio.io istio-system tcpbytesent metric.v1alpha2.config.istio.io ``` If there are no metric instances configured, you will need to reconfigure Mixer with the appropriate instance configuration. 1. Verify Mixer configuration resolution is working for your service. 1. Establish a connection to the Mixer self-monitoring endpoint. Setup a `port-forward` to the Mixer self-monitoring port as described in [Verify Mixer is receiving Report calls](#verify-mixer-is-receiving-report-calls). 1. On the [Mixer self-monitoring port](http://localhost:9093/metrics), search for `mixer_config_resolve_count`. You should find something like: ```plain mixer_config_resolve_count{error="false",target="details.default.svc.cluster.local"} 56 mixer_config_resolve_count{error="false",target="ingress.istio-system.svc.cluster.local"} 67 mixer_config_resolve_count{error="false",target="mongodb.default.svc.cluster.local"} 18 mixer_config_resolve_count{error="false",target="productpage.default.svc.cluster.local"} 59 mixer_config_resolve_count{error="false",target="ratings.default.svc.cluster.local"} 26 mixer_config_resolve_count{error="false",target="reviews.default.svc.cluster.local"} 54 ``` 1. Validate that there are values for `mixer_config_resolve_count` where `target=""` and `error="false"`. If there are only instances where `error="true"` where `target=`, there is likely an issue with Mixer configuration for your service. Logs information is needed to further debug. In Kubernetes environments, retrieve the Mixer logs via: ```command $ kubectl -n istio-system logs mixer ``` Look for errors related to your configuration or your service in the returned logs. More on viewing Mixer configuration can be found [here](/help/faq/mixer/#mixer-self-monitoring) ### Verify Mixer is sending metric instances to the Prometheus adapter 1. Establish a connection to the Mixer self-monitoring endpoint. Setup a `port-forward` to the Mixer self-monitoring port as described in [Verify Mixer is receiving Report calls](#verify-mixer-is-receiving-report-calls). 1. On the [Mixer self-monitoring port](http://localhost:9093/metrics), search for `mixer_adapter_dispatch_count`. You should find something like: ```plain mixer_adapter_dispatch_count{adapter="prometheus",error="false",handler="handler.prometheus.istio-system",meshFunction="metric",response_code="OK"} 114 mixer_adapter_dispatch_count{adapter="prometheus",error="true",handler="handler.prometheus.default",meshFunction="metric",response_code="INTERNAL"} 4 mixer_adapter_dispatch_count{adapter="stdio",error="false",handler="handler.stdio.istio-system",meshFunction="logentry",response_code="OK"} 104 ``` 1. Validate that there are values for `mixer_adapter_dispatch_count` where `adapter="prometheus"` and `error="false"`. If there are are no recorded dispatches to the Prometheus adapter, there is likely a configuration issue. Please see [Verify Mixer metrics configuration exists](#verify-mixer-metrics-configuration-exists). If dispatches to the Prometheus adapter are reporting errors, check the Mixer logs to determine the source of the error. Most likely, there is a configuration issue for the handler listed in `mixer_adapter_dispatch_count`. In Kubernetes environment, check the Mixer logs via: ```command $ kubectl -n istio-system logs mixer ``` Filter for lines including something like `Report 0 returned with: INTERNAL (1 error occurred:` (with some surrounding context) to find more information regarding Report dispatch failures. ### Verify Prometheus configuration 1. Connect to the Prometheus UI and verify that it can successfully scrape Mixer. In Kubernetes environments, setup port-forwarding as follows: ```command $ kubectl -n istio-system port-forward $(kubectl -n istio-system get pod -l app=prometheus -o jsonpath='{.items[0].metadata.name}') 9090:9090 & ``` 1. Visit [http://localhost:9090/targets](http://localhost:9090/targets) and confirm that the target `istio-mesh` has a status of **UP**. 1. Visit [http://localhost:9090/config](http://localhost:9090/config) and confirm that an entry exists that looks like: ```yaml - job_name: 'istio-mesh' # Override the global default and scrape targets from this job every 5 seconds. scrape_interval: 5s # metrics_path defaults to '/metrics' # scheme defaults to 'http'. static_configs: - targets: ['istio-mixer.istio-system:42422'] ``` ## How can I debug issues with the service mesh? ### With istioctl Istioctl allows you to inspect the current xDS of a given Envoy from its admin interface (locally) or from Pilot using the `proxy-config` or `pc` command. For example, to retrieve the configured clusters in an Envoy via the admin interface run the following command: ```command $ istioctl proxy-config endpoint clusters ``` To retrieve endpoints for a given pod in the application namespace from Pilot run the following command: ```command $ istioctl proxy-config pilot -n application eds ``` The `proxy-config` command also allows you to retrieve the state of the entire mesh from Pilot using the following command: ```command $ istioctl proxy-config pilot mesh ads ``` ### With GDB To debug Istio with `gdb`, you will need to run the debug images of Envoy / Mixer / Pilot. A recent `gdb` and the golang extensions (for Mixer/Pilot or other golang components) is required. 1. `kubectl exec -it PODNAME -c [proxy | mixer | pilot]` 1. Find process ID: ps ax 1. gdb -p PID binary 1. For go: info goroutines, goroutine x bt ### With Tcpdump Tcpdump doesn't work in the sidecar pod - the container doesn't run as root. However any other container in the same pod will see all the packets, since the network namespace is shared. `iptables` will also see the pod-wide config. Communication between Envoy and the app happens on 127.0.0.1, and is not encrypted. ## Envoy is crashing under load Check your `ulimit -a`. Many systems have a 1024 open file descriptor limit by default which will cause Envoy to assert and crash with: ```plain [2017-05-17 03:00:52.735][14236][critical][assert] assert failure: fd_ != -1: external/envoy/source/common/network/connection_impl.cc:58 ``` Make sure to raise your ulimit. Example: `ulimit -n 16384` ## Headless TCP services losing connection from Istiofied containers If `istio-citadel` is deployed, Envoy is restarted every 15 minutes to refresh certificates. This causes the disconnection of TCP streams or long-running connections between services. You should build resilience into your application for this type of disconnect, but if you still want to prevent the disconnects from happening, you will need to disable mTLS and the `istio-citadel` deployment. First, edit your istio config to disable mTLS ```command $ kubectl edit configmap -n istio-system istio $ kubectl delete pods -n istio-system -l istio=pilot ``` Next, scale down the `istio-citadel` deployment to disable Envoy restarts. ```command $ kubectl scale --replicas=0 deploy/istio-citadel -n istio-system ``` This should stop Istio from restarting Envoy and disconnecting TCP connections. ## Envoy Process High CPU Usage For larger clusters, the default configuration that comes with Istio refreshes the Envoy configuration every 1 second. This can cause high CPU usage, even when Envoy isn't doing anything. In order to bring the CPU usage down for larger deployments, increase the refresh interval for Envoy to something higher, like 30 seconds. ```command $ kubectl edit configmap -n istio-system istio $ kubectl delete pods -n istio-system -l istio=pilot ``` Also make sure to reinject the sidecar into all of your pods, as their configuration needs to be updated as well. Afterwards, you should see CPU usage fall back to 0-1% while idling. Make sure to tune these values for your specific deployment. *Warning:*: Changes created by routing rules will take up to 2x refresh interval to propagate to the sidecars. While the larger refresh interval will reduce CPU usage, updates caused by routing rules may cause a period of HTTP 404s (up to 2x the refresh interval) until the Envoy sidecars get all relevant configuration. ## Kubernetes webhook setup script files are missing from 0.5 release package > The 0.5.0 and 0.5.1 releases are missing scripts to provision webhook certificates. Download the missing files from [here](https://raw.githubusercontent.com/istio/istio/release-0.7/install/kubernetes/webhook-create-signed-cert.sh) and [here](https://raw.githubusercontent.com/istio/istio/release-0.7/install/kubernetes/webhook-patch-ca-bundle.sh). Subsequent releases (> 0.5.1) include these files. ## Automatic sidecar injection will fail if the kube-apiserver has proxy settings This was tested on 0.5.0 with the additional files required as referenced in the above issue. When the Kube-apiserver included proxy settings such as: ```yaml env: - name: http_proxy value: http://proxy-wsa.esl.foo.com:80 - name: https_proxy value: http://proxy-wsa.esl.foo.com:80 - name: no_proxy value: 127.0.0.1,localhost,dockerhub.foo.com,devhub-docker.foo.com,10.84.100.125,10.84.100.126,10.84.100.127 ``` The sidecar injection would fail. The only related failure logs was in the kube-apiserver log: ```plain W0227 21:51:03.156818 1 admission.go:257] Failed calling webhook, failing open sidecar-injector.istio.io: failed calling admission webhook "sidecar-injector.istio.io": Post https://istio-sidecar-injector.istio-system.svc:443/inject: Service Unavailable ``` Make sure both pod and service CIDRs are not proxied according to *_proxy variables. Check the kube-apiserver files and logs to verify the configuration and whether any requests are being proxied. A workaround is to remove the proxy settings from the kube-apiserver manifest and restart the server or use a later version of kubernetes. An issue was filed in kubernetes related to this and has since been closed. [https://github.com/kubernetes/kubeadm/issues/666](https://github.com/kubernetes/kubeadm/issues/666) [https://github.com/kubernetes/kubernetes/pull/58698#discussion_r163879443](https://github.com/kubernetes/kubernetes/pull/58698#discussion_r163879443)