%3CLINGO-SUB%20id%3D%22lingo-sub-2084778%22%20slang%3D%22en-US%22%3EExperiencing%20Latency%20and%20Data%20Loss%20issue%20in%20Azure%20Portal%20for%20Many%20Data%20Types%20-%2001%2F21%20-%20Resolved%3C%2FLINGO-SUB%3E%3CLINGO-BODY%20id%3D%22lingo-body-2084778%22%20slang%3D%22en-US%22%3E%3CDIV%20style%3D%22font-size%3A14px%3B%22%3E%3CDIV%20style%3D%22font-size%3A14px%3B%22%3E%3CU%3EFinal%20Update%3C%2FU%3E%3A%20Friday%2C%2022%20January%202021%2000%3A08%20UTC%3CBR%20%2F%3E%3CBR%20%2F%3EWe've%20confirmed%20that%20all%20systems%20are%20back%20to%20normal%20with%20no%20customer%20impact%20as%20of%201%2F21%2C%2023%3A56%20UTC.%20Our%20logs%20show%20the%20incident%20started%20on%201%2F21%2C%2021%3A55%20UTC%20and%20that%20during%20the%202%20hours%20and%201%20minute%20that%20it%20took%20to%20resolve%20the%20issue%2013%25%20of%20customers%20in%20West%20US%202%20and%2028%25%20of%20customers%20in%20West%20US%20with%20workspace-enabled%20Application%20Insights%20resources%20experienced%20intermittent%20data%20gaps%20and%20latent%20data%20as%20well%20as%20possible%20misfiring%20of%20alerts%20based%20on%20such%20data%20gaps%20or%20latencies.%3CBR%20%2F%3E%3CUL%3E%3CLI%3E%3CU%3ERoot%20Cause%3C%2FU%3E%3A%20The%20failure%20was%20due%20to%20a%20backend%20cache%20issue%20encountering%20a%20threshold.%20The%20resource%20was%20scaled%20out%20to%20handle%20the%20expanded%20load%20in%20the%20region.%3C%2FLI%3E%3CLI%3E%3CU%3EIncident%20Timeline%3C%2FU%3E%3A%202%20Hours%20%26amp%3B%201%20minutes%20-%201%2F21%2C%2021%3A55%20UTC%26nbsp%3Bthrough%201%2F21%2C%2023%3A56%20UTC%3C%2FLI%3E%3C%2FUL%3EWe%20understand%20that%20customers%20rely%20on%20Application%20Insights%20as%20a%20critical%20service%20and%20apologize%20for%20any%20impact%20this%20incident%20caused.%3CBR%20%2F%3E%3CBR%20%2F%3E-Jeff%3CBR%20%2F%3E%3C%2FDIV%3E%3CHR%20style%3D%22border-top-color%3Alightgray%22%20%2F%3E%3CDIV%20style%3D%22font-size%3A14px%3B%22%3E%3CDIV%20style%3D%22font-size%3A14px%3B%22%3E%3CU%3EUpdate%3C%2FU%3E%3A%20Thursday%2C%2021%20January%202021%2022%3A59%20UTC%3CBR%20%2F%3E%3CBR%20%2F%3ERoot%20cause%20has%20been%20isolated%20to%20a%20backend%20component%20scale%20issue%20which%20was%20impacting%20customers%20with%20workspace-enabled%20Application%20Insights%20resources%20in%20West%20US2%20and%20West%20US%20regions.%20To%20address%20this%20issue%20we%20are%20investigating%20scaling%20options%20in%20the%20backend%20components.%26nbsp%3B%3CBR%20%2F%3E%3CUL%3E%3CLI%3E%3CU%3EWork%20Around%3C%2FU%3E%3A%20None%3C%2FLI%3E%3CLI%3E%3CU%3ENext%20Update%3C%2FU%3E%3A%20Before%2001%2F22%2001%3A00%20UTC%3C%2FLI%3E%3C%2FUL%3E-Jeff%3CBR%20%2F%3E%3C%2FDIV%3E%3CHR%20style%3D%22border-top-color%3Alightgray%22%20%2F%3E%3CDIV%20style%3D%22font-size%3A14px%3B%22%3E%3CDIV%20style%3D%22font-size%3A14px%3B%22%3E%3CU%3EInitial%20Update%3C%2FU%3E%3A%20Thursday%2C%2021%20January%202021%2022%3A33%20UTC%3CBR%20%2F%3E%3CBR%20%2F%3EWe%20are%20aware%20of%20issues%20within%20Application%20Insights%20and%20are%20actively%20investigating.%20Some%20customers%20may%20experience%20delayed%20or%20missed%20Log%20Search%20Alerts%20and%20Latency%20and%20Data%20Loss.%3CUL%3E%3CLI%3E%3CU%3ENext%20Update%3C%2FU%3E%3A%20Before%2001%2F22%2001%3A00%20UTC%3C%2FLI%3E%3C%2FUL%3EWe%20are%20working%20hard%20to%20resolve%20this%20issue%20and%20apologize%20for%20any%20inconvenience.%3CBR%20%2F%3E-Jeff%3C%2FDIV%3E%3CHR%20style%3D%22border-top-color%3Alightgray%22%20%2F%3E%3C%2FDIV%3E%3C%2FDIV%3E%3C%2FDIV%3E%3C%2FLINGO-BODY%3E%3CLINGO-LABS%20id%3D%22lingo-labs-2084778%22%20slang%3D%22en-US%22%3E%3CLINGO-LABEL%3EApplication%20Insights%3C%2FLINGO-LABEL%3E%3C%2FLINGO-LABS%3E
Final Update: Friday, 22 January 2021 00:08 UTC

We've confirmed that all systems are back to normal with no customer impact as of 1/21, 23:56 UTC. Our logs show the incident started on 1/21, 21:55 UTC and that during the 2 hours and 1 minute that it took to resolve the issue 13% of customers in West US 2 and 28% of customers in West US with workspace-enabled Application Insights resources experienced intermittent data gaps and latent data as well as possible misfiring of alerts based on such data gaps or latencies.
  • Root Cause: The failure was due to a backend cache issue encountering a threshold. The resource was scaled out to handle the expanded load in the region.
  • Incident Timeline: 2 Hours & 1 minutes - 1/21, 21:55 UTC through 1/21, 23:56 UTC
We understand that customers rely on Application Insights as a critical service and apologize for any impact this incident caused.

-Jeff

Update: Thursday, 21 January 2021 22:59 UTC

Root cause has been isolated to a backend component scale issue which was impacting customers with workspace-enabled Application Insights resources in West US2 and West US regions. To address this issue we are investigating scaling options in the backend components. 
  • Work Around: None
  • Next Update: Before 01/22 01:00 UTC
-Jeff

Initial Update: Thursday, 21 January 2021 22:33 UTC

We are aware of issues within Application Insights and are actively investigating. Some customers may experience delayed or missed Log Search Alerts and Latency and Data Loss.
  • Next Update: Before 01/22 01:00 UTC
We are working hard to resolve this issue and apologize for any inconvenience.
-Jeff