=============== Troubleshooting =============== This chapter is intended to help troubleshoot and resolve operational issues in an OpenStack-Ansible deployment. Networking ~~~~~~~~~~ This section focuses on troubleshooting general host-to-host communication required for the OpenStack control plane to function properly. This does not cover any networking related to instance connectivity. These instructions assume an OpenStack-Ansible installation using LXC containers, VXLAN overlay, and the Linuxbridge ml2 driver. Network List ------------ 1. ``HOST_NET`` (Physical Host Management and Access to Internet) 2. ``CONTAINER_NET`` (LXC container network used Openstack Services) 3. ``OVERLAY_NET`` (VXLAN overlay network) Useful network utilities and commands: .. code-block:: console # ip link show [dev INTERFACE_NAME] # arp -n [-i INTERFACE_NAME] # ip [-4 | -6] address show [dev INTERFACE_NAME] # ping # tcpdump [-n -nn] < -i INTERFACE_NAME > [host SOURCE_IP_ADDRESS] # brctl show [BRIDGE_ID] # iptables -nL # arping [-c NUMBER] [-d] Troubleshooting host-to-host traffic on HOST_NET ------------------------------------------------ Perform the following checks: - Check physical connectivity of hosts to physical network - Check interface bonding (if applicable) - Check VLAN configurations and any necessary trunking to edge ports on physical switch - Check VLAN configurations and any necessary trunking to uplink ports on physical switches (if applicable) - Check that hosts are in the same IP subnet or have proper routing between them - Check there are no iptables applied to the hosts that would deny traffic IP addresses should be applied to physical interface, bond interface, tagged sub-interface, or in some cases the bridge interface: .. code-block:: console # ip address show dev bond0 14: bond0: mtu 1500..UP... link/ether a0:a0:a0:a0:a0:01 brd ff:ff:ff:ff:ff:ff inet 10.240.0.44/22 brd 10.240.3.255 scope global bond0 valid_lft forever preferred_lft forever ... Troubleshooting host-to-host traffic on CONTAINER_NET ----------------------------------------------------- Perform the following checks: - Check physical connectivity of hosts to physical network - Check interface bonding (if applicable) - Check VLAN configurations and any necessary trunking to edge ports on physical switch - Check VLAN configurations and any necessary trunking to uplink ports on physical switches (if applicable) - Check that hosts are in the same subnet or have proper routing between them - Check there are no iptables applied to the hosts that would deny traffic - Check to verify that physical interface is in the bridge - Check to verify that veth-pair end from container is in ``br-mgmt`` IP address should be applied to ``br-mgmt``: .. code-block:: console # ip address show dev br-mgmt 18: br-mgmt: mtu 1500...UP... link/ether a0:a0:a0:a0:a0:01 brd ff:ff:ff:ff:ff:ff inet 172.29.236.44/22 brd 172.29.239.255 scope global br-mgmt valid_lft forever preferred_lft forever ... IP address should be applied to ``eth1`` inside the LXC container: .. code-block:: console # ip address show dev eth1 59: eth1: mtu 1500...UP... link/ether b1:b1:b1:b1:b1:01 brd ff:ff:ff:ff:ff:ff inet 172.29.236.55/22 brd 172.29.239.255 scope global eth1 valid_lft forever preferred_lft forever ... ``br-mgmt`` should contain veth-pair ends from all containers and a physical interface or tagged-subinterface: .. code-block:: console # brctl show br-mgmt bridge name bridge id STP enabled interfaces br-mgmt 8000.abcdef12345 no 11111111_eth1 22222222_eth1 ... bond0.100 99999999_eth1 ... Troubleshooting host-to-host traffic on OVERLAY_NET --------------------------------------------------- Perform the following checks: - Check physical connectivity of hosts to physical network - Check interface bonding (if applicable) - Check VLAN configurations and any necessary trunking to edge ports on physical switch - Check VLAN configurations and any necessary trunking to uplink ports on physical switches (if applicable) - Check that hosts are in the same subnet or have proper routing between them - Check there are no iptables applied to the hosts that would deny traffic - Check to verify that physcial interface is in the bridge - Check to verify that veth-pair end from container is in ``br-vxlan`` IP address should be applied to ``br-vxlan``: .. code-block:: console # ip address show dev br-vxlan 21: br-vxlan: mtu 1500...UP... link/ether a0:a0:a0:a0:a0:02 brd ff:ff:ff:ff:ff:ff inet 172.29.240.44/22 brd 172.29.243.255 scope global br-vxlan valid_lft forever preferred_lft forever ... Checking services ~~~~~~~~~~~~~~~~~ You can check the status of an OpenStack service by accessing every controller node and running the :command:`service status`. See the following links for additional information to verify OpenStack services: - `Identity service (keystone) `_ - `Image service (glance) `_ - `Compute service (nova) `_ - `Networking service (neutron) `_ - `Block Storage service `_ - `Object Storage service (swift) `_ Restarting services ~~~~~~~~~~~~~~~~~~~ Restart your OpenStack services by accessing every controller node. Some OpenStack services will require restart from other nodes in your environment. The following table lists the commands to restart an OpenStack service. .. list-table:: Restarting OpenStack services :widths: 30 70 :header-rows: 1 * - OpenStack service - Commands * - Image service - .. code-block:: console # service glance-api restart * - Compute service (controller node) - .. code-block:: console # service nova-api-os-compute restart # service nova-consoleauth restart # service nova-scheduler restart # service nova-conductor restart # service nova-api-metadata restart # service nova-novncproxy restart (if using novnc) # service nova-spicehtml5proxy restart (if using spice) * - Compute service (compute node) - .. code-block:: console # service nova-compute restart * - Networking service - .. code-block:: console # service neutron-server restart # service neutron-dhcp-agent restart # service neutron-l3-agent restart # service neutron-metadata-agent restart # service neutron-linuxbridge-agent restart * - Networking service (compute node) - .. code-block:: console # service neutron-linuxbridge-agent restart * - Block Storage service - .. code-block:: console # service cinder-api restart # service cinder-backup restart # service cinder-scheduler restart # service cinder-volume restart * - Block Storage service - .. code-block:: console # service manila-api restart # service manila-data restart # service manila-share restart # service manila-scheduler restart * - Object Storage service - .. code-block:: console # service swift-account-auditor restart # service swift-account-server restart # service swift-account-reaper restart # service swift-account-replicator restart # service swift-container-auditor restart # service swift-container-server restart # service swift-container-reconciler restart # service swift-container-replicator restart # service swift-container-sync restart # service swift-container-updater restart # service swift-object-auditor restart # service swift-object-expirer restart # service swift-object-server restart # service swift-object-reconstructor restart # service swift-object-replicator restart # service swift-object-updater restart # service swift-proxy-server restart Troubleshooting Instance connectivity issues ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This section will focus on troubleshooting general instance (VM) connectivity communication. This does not cover any networking related to instance connectivity. This is assuming a OpenStack-Ansible install using LXC containers, VXLAN overlay and the Linuxbridge ml2 driver. **Data flow example** .. code-block:: console COMPUTE NODE +-------------+ +-------------+ +->"If VXLAN"+->+ *br vxlan +--->+ bond#.#00 +---+ | +-------------+ +-------------+ | +-------------+ | +-----------------+ Instance +---> | brq bridge |++ +-->| physical network| +-------------+ | +-----------------+ | +-------------+ +-------------+ | +->"If VLAN"+->+ br vlan +--->+ bond1 +---+ +-------------+ +-------------+ NETWORK NODE +-------------+ +-------------+ +->"If VXLAN"+->+ *bond#.#00 +--->+ *br vxlan +--> | +-------------+ +-------------+ | +----------------+ | +-------------+ |physical network|++ +--->+| brq bridge |+--> Neutron DHCP/Router +----------------+ | +-------------+ | +-------------+ +-------------+ | +->"If VLAN"+->+ bond1 +--->+ br vlan +--> +-------------+ +-------------+ Preliminary troubleshooting questions to answer: ------------------------------------------------ - Which compute node is hosting the VM in question? - Which interface is used for provider network traffic? - Which interface is used for VXLAN overlay? - Is the connectivity issue ingress to the instance? - Is the connectivity issue egress from the instance? - What is the source address of the traffic? - What is the destination address of the traffic? - Is there a Neutron router in play? - Which network node (container) is the router hosted? - What is the tenant network type? If VLAN: Does physical interface show link and all VLANs properly trunked across physical network? No: - Check cable, seating, physical switchport configuration, interface/bonding configuration, and general network configuration. See general network troubleshooting documentation. Yes: - Good! - Continue! .. important:: Do not continue until physical network is properly configured. Does the instance's IP address ping from network's DHCP namespace or other instances in the same network? No: - Check nova console logs to see if the instance ever received its IP address initially. - Check Neutron ``security-group-rules``, consider adding allow ICMP rule for testing. - Check that linux bridges contain the proper interfaces. on compute and network nodes. - Check Neutron DHCP agent logs. - Check syslogs. - Check Neutron linux bridge logs. Yes: - Good! This suggests that the instance received its IP address and can reach local network resources. - Continue! .. important:: Do not continue until instance has an IP address and can reach local network resources like DHCP. Does the instance's IP address ping from the gateway device (Neutron router namespace or another gateway device)? No: - Check Neutron L3 agent logs (if applicable). - Check Neutron linuxbridge logs. - Check physical interface mappings. - Check Neutron Router ports (if applicable). - Check that linux bridges contain the proper interfaces on compute and network nodes. - Check Neutron ``security-group-rules``, consider adding allow ICMP rule for testing. Yes: - Good! The instance can ping its intended gateway. The issue may be north of the gateway or related to the provider network. - Check "gateway" or host routes on the Neutron subnet. - Check Neutron ``security-group-rules``, consider adding ICMP rule for testing. - Check Neutron FloatingIP associations (if applicable). - Check Neutron Router external gateway information (if applicable). - Check upstream routes, NATs or access-control-lists. .. important:: Do not continue until the instance can reach its gateway. If VXLAN: Does physical interface show link and all VLANs properly trunked across physical network? No: - Check cable, seating, physical switchport configuration, interface/bonding configuration, and general network configuration. See general network troubleshooting documentation. Yes: - Good! - Continue! .. important:: Do not continue until physical network is properly configured. Are VXLAN VTEP addresses able to ping each other? No: - Check ``br-vxlan`` interface on Compute and Network nodes - Check veth pairs between containers and linux bridges on the host. - Check that linux bridges contain the proper interfaces on compute and network nodes. Yes: - Check ml2 config file for local VXLAN IP and other VXLAN configuration settings. - Check VTEP learning method (multicast or l2population): - If multicast, make sure the physical switches are properly allowing and distributing multicast traffic. .. important:: Do not continue until VXLAN endpoints have reachability to each other. Does the instance's IP address ping from network's DHCP namespace or other instances in the same network? No: - Check Nova console logs to see if the instance ever received its IP address initially. - Check Neutron ``security-group-rules``, consider adding allow ICMP rule for testing. - Check that linux bridges contain the proper interfaces on compute and network nodes. - Check Neutron DHCP agent logs. - Check syslogs. - Check Neutron linux bridge logs. - Check that Bridge Forwarding Database (fdb) contains the proper entries on both the compute and Neutron agent container. Yes: - Good! This suggests that the instance received its IP address and can reach local network resources. .. important:: Do not continue until instance has an IP address and can reach local network resources. Does the instance's IP address ping from the gateway device (Neutron router namespace or another gateway device)? No: - Check Neutron L3 agent logs (if applicable). - Check Neutron linux bridge logs. - Check physical interface mappings. - Check Neutron router ports (if applicable). - Check that linux bridges contain the proper interfaces on compute and network nodes. - Check Neutron ``security-group-rules``, consider adding allow ICMP rule for testing. - Check that Bridge Forwarding Database (fdb) contains the proper entries on both the compute and Neutron agent container. Yes: - Good! The instance can ping its intended gateway. - Check gateway or host routes on the Neutron subnet. - Check Neutron ``security-group-rules``, consider adding ICMP rule for testing. - Check Neutron FloatingIP associations (if applicable). - Check Neutron Router external gateway information (if applicable). - Check upstream routes, NATs or ``access-control-lists``. Diagnose Image service issues ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The ``glance-api`` handles the API interactions and image store. To troubleshoot problems or errors with the Image service, refer to :file:`/var/log/glance-api.log` inside the glance api container. You can also conduct the following activities which may generate logs to help identity problems: #. Download an image to ensure that an image can be read from the store. #. Upload an image to test whether the image is registering and writing to the image store. #. Run the ``openstack image list`` command to ensure that the API and registry is working. For an example and more information, see `Verify operation _`. and `Manage Images _` RabbitMQ issues ~~~~~~~~~~~~~~~ Analyze RabbitMQ queues ----------------------- .. The title should state what issue is being resolved? DC Analyze OpenStack service logs and RabbitMQ logs ------------------------------------------------ .. The title should state what issue is being resolved? DC Failed security hardening after host kernel upgrade from version 3.13 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Ubuntu kernel packages newer than version 3.13 contain a change in module naming from ``nf_conntrack`` to ``br_netfilter``. After upgrading the kernel, run the ``openstack-hosts-setup.yml`` playbook against those hosts. For more information, see `OSA bug 157996 `_. Cached Ansible facts issues ~~~~~~~~~~~~~~~~~~~~~~~~~~~ At the beginning of a playbook run, information about each host is gathered, such as: * Linux distribution * Kernel version * Network interfaces To improve performance, particularly in large deployments, you can cache host facts and information. OpenStack-Ansible enables fact caching by default. The facts are cached in JSON files within ``/etc/openstack_deploy/ansible_facts``. Fact caching can be disabled by running ``export ANSIBLE_CACHE_PLUGIN=memory``. To set this permanently, set this variable in ``/usr/local/bin/openstack-ansible.rc``. Refer to the Ansible documentation on `fact caching`_ for more details. .. _fact caching: https://docs.ansible.com/ansible/latest/user_guide/playbooks_variables.html#fact-caching Forcing regeneration of cached facts ------------------------------------ Cached facts may be incorrect if the host receives a kernel upgrade or new network interfaces. Newly created bridges also disrupt cache facts. This can lead to unexpected errors while running playbooks, and require cached facts to be regenerated. Run the following command to remove all currently cached facts for all hosts: .. code-block:: shell-session # rm /etc/openstack_deploy/ansible_facts/* New facts will be gathered and cached during the next playbook run. To clear facts for a single host, find its file within ``/etc/openstack_deploy/ansible_facts/`` and remove it. Each host has a JSON file that is named after its hostname. The facts for that host will be regenerated on the next playbook run. Failed ansible playbooks during an upgrade ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Container networking issues ~~~~~~~~~~~~~~~~~~~~~~~~~~~ All LXC containers on the host have at least two virtual Ethernet interfaces: * `eth0` in the container connects to `lxcbr0` on the host * `eth1` in the container connects to `br-mgmt` on the host .. note:: Some containers, such as ``cinder``, ``glance``, ``neutron_agents``, and ``swift_proxy`` have more than two interfaces to support their functions. Predictable interface naming ---------------------------- On the host, all virtual Ethernet devices are named based on their container as well as the name of the interface inside the container: .. code-block:: shell-session ${CONTAINER_UNIQUE_ID}_${NETWORK_DEVICE_NAME} As an example, an all-in-one (AIO) build might provide a utility container called `aio1_utility_container-d13b7132`. That container will have two network interfaces: `d13b7132_eth0` and `d13b7132_eth1`. Another option would be to use the LXC tools to retrieve information about the utility container. For example: .. code-block:: shell-session # lxc-info -n aio1_utility_container-d13b7132 Name: aio1_utility_container-d13b7132 State: RUNNING PID: 8245 IP: 10.0.3.201 IP: 172.29.237.204 CPU use: 79.18 seconds BlkIO use: 678.26 MiB Memory use: 613.33 MiB KMem use: 0 bytes Link: d13b7132_eth0 TX bytes: 743.48 KiB RX bytes: 88.78 MiB Total bytes: 89.51 MiB Link: d13b7132_eth1 TX bytes: 412.42 KiB RX bytes: 17.32 MiB Total bytes: 17.73 MiB The ``Link:`` lines will show the network interfaces that are attached to the utility container. Review container networking traffic ----------------------------------- To dump traffic on the ``br-mgmt`` bridge, use ``tcpdump`` to see all communications between the various containers. To narrow the focus, run ``tcpdump`` only on the desired network interface of the containers. Restoring inventory from backup ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ OpenStack-Ansible maintains a running archive of inventory. If a change has been introduced into the system that has broken inventory or otherwise has caused an unforseen issue, the inventory can be reverted to an early version. The backup file ``/etc/openstack_deploy/backup_openstack_inventory.tar`` contains a set of timestamped inventories that can be restored as needed. Example inventory restore process. .. code-block:: bash mkdir /tmp/inventory_restore cp /etc/openstack_deploy/backup_openstack_inventory.tar /tmp/inventory_restore/backup_openstack_inventory.tar cd /tmp/inventory_restore tar xf backup_openstack_inventory.tar # Identify the inventory you wish to restore as the running inventory cp openstack_inventory.json-YYYYMMDD_SSSSSS.json /etc/openstack_deploy/openstack_inventory.json cd - rm -rf /tmp/inventory_restore At the completion of this operation the inventory will be restored to the earlier version.