Debugging and Internal Statistics¶

VirtUI Manager provides built-in tools to help users debug issues and monitor the application's internal performance, including lru_cache usage and libvirt API call statistics.

Accessing Debug Information¶

You can access debug information and internal statistics directly from within the VirtUI Manager application using keyboard shortcuts:

Ctrl+L: Toggles the Log Viewer modal. This modal displays recent application logs, which can be useful for identifying errors or unexpected behavior.
Ctrl+S: Opens the Cache Statistics modal. This modal provides detailed insights into the lru_cache hit rates and usage patterns for various internal functions, as well as a summary of libvirt API calls.

Cache Monitoring¶

The Cache Statistics modal (Ctrl+S) presents a breakdown of how effectively the application's caching mechanisms are working. High hit rates indicate efficient data retrieval, while low hit rates might suggest areas for optimization.

Cache stats

Here's an example of the cache statistics output in the log:

INFO - Cache monitoring enabled.
INFO - === Cache Statistics ===
INFO - format_server_names: 0.0% hit rate (0 hits, 0 misses, 0/8 entries)
INFO - extract_server_name_from_uri: 95.7% hit rate (44 hits, 2 misses, 2/16 entries)
INFO - get_server_color_cached: 93.5% hit rate (72 hits, 5 misses, 5/16 entries)
INFO - natural_sort_key: 85.0% hit rate (108 hits, 19 misses, 19/512 entries)
INFO - format_memory_display: 77.8% hit rate (14 hits, 4 misses, 4/128 entries)
INFO - generate_tooltip_markdown: 57.1% hit rate (24 hits, 18 misses, 18/128 entries)
INFO - get_host_pci_devices: 33.3% hit rate (1 hits, 2 misses, 2/4 entries)
INFO - get_host_usb_devices: 33.3% hit rate (1 hits, 2 misses, 2/4 entries)
INFO - get_domain_capabilities_xml: 0.0% hit rate (0 hits, 3 misses, 3/4 entries)
INFO - _parse_domain_xml: 75.0% hit rate (24 hits, 8 misses, 8/256 entries)
INFO - get_vm_description: 0.0% hit rate (0 hits, 3 misses, 3/16 entries)
INFO - get_vm_disks_info: 0.0% hit rate (0 hits, 13 misses, 13/256 entries)
INFO - get_vm_disks: 0.0% hit rate (0 hits, 0 misses, 0/32 entries)
INFO - get_boot_info: 0.0% hit rate (0 hits, 7 misses, 7/32 entries)
INFO - get_all_vm_disk_usage: 0.0% hit rate (0 hits, 1 misses, 1/32 entries)
INFO - get_supported_machine_types: 0.0% hit rate (0 hits, 0 misses, 0/32 entries)
INFO - list_storage_pools: 0.0% hit rate (0 hits, 1 misses, 1/16 entries)
INFO - list_storage_volumes: 0.0% hit rate (0 hits, 0 misses, 0/32 entries)
INFO - find_vms_using_volume: 0.0% hit rate (0 hits, 0 misses, 0/32 entries)
INFO - get_all_storage_volumes: 0.0% hit rate (0 hits, 0 misses, 0/16 entries)
INFO - list_networks: 40.0% hit rate (2 hits, 3 misses, 3/16 entries)
INFO - get_vms_using_network: 0.0% hit rate (0 hits, 0 misses, 0/16 entries)
INFO - get_host_network_info: 0.0% hit rate (0 hits, 0 misses, 0/32 entries)

Libvirt Call Statistics¶

This section, also available through Ctrl+S, details the number of calls made to various libvirt API functions, broken down by connection (server). This is invaluable for understanding the application's interaction with libvirt and identifying potential API hotspots.

Here's an example of the libvirt call statistics output:

INFO - === Libvirt Call Statistics ===
INFO - ryzen7 (qemu+ssh://root @10.0.1.78/system): 2060 calls | +22 (100.0%)
INFO -   - name: 748 calls (+10)
INFO -   - connect: 379 calls (+3)
INFO -   - blockStats: 188 calls (+2)
INFO -   - info: 126 calls (+1)
INFO -   - state: 104 calls (+1)
INFO -   - getCPUStats: 94 calls (+1)
INFO -   - memoryStats: 94 calls (+1)
INFO -   - interfaceStats: 94 calls (+1)
INFO -   - interfaceAddresses: 94 calls (+1)
INFO -   - getURI: 40 calls (+0)
INFO -   - XMLDesc: 36 calls (+0)
INFO -   - listAllDomains: 32 calls (+1)
INFO -   - UUIDString: 9 calls (+0)
INFO -   - snapshotNum: 5 calls (+0)
INFO -   - listAllSnapshots: 3 calls (+0)
INFO -   - listAllNetworks: 2 calls (+0)
INFO -   - listAllDevices: 2 calls (+0)
INFO -   - registerCloseCallback: 1 calls (+0)
INFO -   - domainEventRegisterAny: 1 calls (+0)
INFO -   - metadata: 1 calls (+0)
INFO -   - getCPUModelNames: 1 calls (+0)
INFO -   - getDomainCapabilities: 1 calls (+0)
INFO -   - isActive: 1 calls (+0)
INFO -   - getHostname: 1 calls (+0)
INFO -   - numOfDomains: 1 calls (+0)
INFO -   - numOfDefinedDomains: 1 calls (+0)
INFO -   - listAllStoragePools: 1 calls (+0)
INFO - g.org (qemu+ssh://root @REMOTEURL:PORT/system): 386 calls | +27 (100.0%)
INFO -   - name: 170 calls (+15)
INFO -   - connect: 56 calls (+3)
INFO -   - getURI: 22 calls (+0)
INFO -   - info: 22 calls (+1)
INFO -   - blockStats: 20 calls (+2)
INFO -   - state: 19 calls (+1)
INFO -   - UUIDString: 14 calls (+0)
INFO -   - getCPUStats: 10 calls (+1)
INFO -   - memoryStats: 10 calls (+1)
INFO -   - interfaceStats: 10 calls (+1)
INFO -   - interfaceAddresses: 10 calls (+1)
INFO -   - XMLDesc: 6 calls (+0)
INFO -   - listAllDomains: 5 calls (+1)
INFO -   - snapshotNum: 5 calls (+0)
INFO -   - listAllNetworks: 2 calls (+0)
INFO -   - listAllDevices: 2 calls (+0)
INFO -   - registerCloseCallback: 1 calls (+0)
INFO -   - domainEventRegisterAny: 1 calls (+0)
INFO -   - storagePoolLookupByName: 1 calls (+0)
INFO -   - shutdown: 1 calls (+0)
INFO -   - create: 1 calls (+0)