Technical Tip: Performance SLA and SD-WAN Rule Pages on FortiGate GUI Interface Fails to Load due to API Overhead

[ssanga]

Description	This article describes an issue where SD-WAN Rules Pages on the FortiGate GUI Interface fail to load in large-scale ADVPN deployments with numerous spokes. This issue is often accompanied by missing visual data in the SD-WAN Zone section. Specifically, the live charts for packet loss, latency, and jitter do not display, and the donut charts for bandwidth, volume, and session metrics show no results.
Scope	FortiGate v7.4.5
Solution	The SD-WAN Rules page fails to load in ADVPN setups, particularly in large environments with numerous spokes. The live chart displaying packet loss, latency, or jitter for the selected health check does not appear. Additionally, the donut charts for Bandwidth, Volume, and Sessions in the SD-WAN Zone view show no data or results. The following logs are seen in the httpsd debugs and crashlog output. diagnose debug application httpsd -1 diagnose debug enable 13:13:49 [httpsd 1863 - 1730805229 info] fweb_debug_init[531] -- New GET request for "/api/v2/monitor/virtual-wan/health-check" from "10.10.0.10:57489" 13:13:49 [httpsd 1863 - 1730805229 info] fweb_debug_init[533] -- User-Agent: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, likeGecko) Chrome/130.0.0.0 Safari/537.36" 13:13:49 [httpsd 1863 - 1730805229 info] fweb_debug_init[535] -- Handler "api_monitor_v2-handler" assigned to request 13:13:49 [httpsd 1863 - 1730805229 info] api_store_parameter[334] -- add API parameter 'vdom' (type=string) 13:13:49 [httpsd 1863 - 1730805229 info] endpoint_process_req_vdom[1084] -- new API request (action='select',path='virtual-wan',name='health-check',vdom='root',user='test') 13:13:49 2024-11-05 13:13:49 [httpsd 1863 - 1730805229 info] lnkmtd_query_intf_stats[5152] -- lnkmtd query thread started. 13:13:49 [httpsd 1863 - 1730805229 info] emit_linkmon_stats_non_blocking[5071] -- Emitting status of interface: wan 13:13:49 [httpsd 1863 - 1730805229 info] emit_linkmon_stats_non_blocking[5071] -- Emitting status of interface: wan 13:13:49 [httpsd 1863 - 1730805229 info] emit_linkmon_stats_non_blocking[5071] -- Emitting status of interface: wan 13:13:49 [httpsd 1863 - 1730805229 info] emit_linkmon_stats_non_blocking[5071] -- Emitting status of interface: lan1 13:13:49 [httpsd 1863 - 1730805229 info] lnkmtd_query_intf_stats[5210] -- Querying link status of interface: wan 13:13:49 [httpsd 1863 - 1730805229 error] virtualwan_health_check[5359] -- Failed to query interface info. 13:13:49 [httpsd 1863 - 1730805229 error] api_return_http_result[1309] -- API error 500 raised diagnose debug crashlog read 17:12:41 httpsd [1321] error=-100, method=GET, uri=/api/v2/monitor/virtual-wan/health-ch 17:12:41 eck 17:12:49 httpsd [1320] error=-100, method=GET, uri=/api/v2/monitor/virtual-wan/health-ch 17:12:49 eck 17:12:50 httpsd [1320] error=-100, method=GET, uri=/api/v2/monitor/virtual-wan/health-ch 17:12:50 eck Crash log interval is 3600 seconds Max crash log line number: 16384 This issue has been resolved in v7.4.8. General debug information required by FortiGate TAC for investigation: Debugs: diagnose debug reset diagnose debug console timestamp enable diagnose debug application httpsd -1 diagnose debug enable <reproduce the issue> diagnose debug reset diagnose debug disable TAC Report: execute tac report The configuration file of the FortiGate. FortiGate Support Tool data: Troubleshooting Tip: Collect GUI slowness and errors debugs via Fortinet Support Tool.