Troubleshooting Application Problems Flashcards
Diagnostic session
- directs AppDynamics to collect extra transaction snapshots for one or more BTs for a period of time
A full call graph
captures the entire call sequence for the business transaction invocation, and contains information on each monitored node involved in the processing of the business transaction.
Snapshots under normal circumstances:
many of these snapshots contain partial call graphs, or no call graphs at all.
Ways to trigger diagnostic session
- Manually
- Automatically in response to performance problems (partial call graph)
- In a responce to an event via policy
Manual diagnostic session parameters
- duration: from 1 to 10 minutes
- frequency: from 1 to 10 snapshots
Slow / Error transaction default threshold
Configuration. => Slow transaction threshold => diagnostic session settings
- More than 10% of calls per minute have errors
- More than 10% of calls are slow / very slow / stalled
Automated Transaction Diagnostics
- uses statistical analysis to identify transaction snapshots for anomalies that could cause issues in the future.
- These snapshots may not have triggered a Health Alert.
- delivers a prioritized list of causal factor transactions that you can use to manage problematic business transactions before they become actual production issues or outages.
How AppDynamics Defines errors
- Any Unhandled exception
- HTTP return codes 400-505 that occur in BT
- An exception that is handled but logged with a severity of Error or Fatal using Log4j or java.util.logging NLog or Log4Net
- A handled exception that occurs during a call to an exit point
NB: There is not a one-to-one correspondence between the number of errors and the number of exceptions.
Configuration > Instrumentation > Error Detection.
A stack trace is available for a given exception if
the exception was passed in the log call.
Stall transaction definition
- Disable detection
- Stall occurs when a transaction’s response time is <300> deviations above average for the last 2 hours
Slow / Error transaction setting options
Select one of the options:
- More than X % slower than the average of the last Y hours
- Greater than X ms
- (Default) Greater than 3 (4) standard deviations for the last Y (2) hour
Configure periodic snapshot collection
- Configuration => Slow transaction snapshots => Tab: diagnostic session settings: Configure periodic snapshot collection
Periodic snapshot collection settings options
(can be both)
- Take one snapshot every X (100) execution of a BT (not recommended for PROD)
- Take one snapshot every X (10) min (Default)
Troubleshoot options
- Slow response times (BT, )
- Errors
- Health rules violations
- War room
Error detection options
- Using logged exceptions or messages
- HTTP return code
- Redirect pages