finish exception

monolith_analysis/slides.Rmd

@@ -1,14 +1,14 @@
 ---
-title: Monolith (analysis)
-lab: none this week
+title: Monolith (analysis - midterm review)
+lab: https://github.com/rhildred/info8985_monolith_analysis
 ---
 ## Agenda
 
-- Review instrumentation for assignment 1
+- Review instrumentation from [last week](`r rmarkdown::metadata$lab`) for assignment 1
 - Review the learning outcomes for the midterm
 - Work period on assignment 1
 
-Based on chapter 1-5 in text
+Based on chapter 1-5 in text and notes summarized here.
 
 ## The midterm is 4 written response questions
 
@@ -25,9 +25,63 @@ Based on chapter 1-5 in text
 
 ## Test for deficiencies
 
+- A dev-ops team would ultimately write a failing test that exposes the root cause of a system outage, make the test pass and deploy through continuous integration.
+- Monitoring and logging helps get to the root cause of a problem a customer may be facing
+- In chapter 4 of the book, we looked at different things we can learn from the otel demo
+- correlate what the customer is seeing with metrics ... for instance
+
+## Relate REDS metrics to what the customer is seeing
+
+- use metric attributes to drill down to the subsystem
+- compare REDS metrics to what the customer is seeing
+- errors for instance will be above the baseline established previously if customers are seeing errors
 
 ## Separate tracing from handling
 
+```python
+from opentelemetry import trace
+span = trace.get_current_span()
+except ValueError as exc:
+    # Record the exception and update the span status.
+    span.record_exception(exc)
+    span.set_status(trace.Status(trace.StatusCode.ERROR, str(exc)))
+    raise
+```
+
+## Separate logging from handling
+
+```python
+import traceback
+import logging
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+try:
+    do_something_that_might_error()
+except Exception as error:
+    logger.debug(traceback.format_exc())
+    raise
+```
+
+## Separate Metric from handling
+
+```python
+try:
+    do_something_that_might_error()
+except:
+    error_counter.add(1, {"error.module": __name__})
+    raise
+```
+
+## Always remember to raise
+
+```python
+except ValueError as exc:
+    ...
+    raise
+```
+- critical so that the calling app can deal with the exception
+
+
 ## Metric baselines
 
 ## Supporting Evidence