add ana skill

Author: haochengxia

agentic/SKILL.md

@@ -0,0 +1,26 @@
+---
+name: trace analysis
+description: Explains the behavior of traces, we focus on analyzing why a trace works different under the same best parameters but different initial stats.
+---
+
+Background: we are working on a learned cache project, basic idea is:
+for a trace, we use first 20% traces for feature extraction, then we use this feature to predict the best parameters for the remaining 80% traces. However, in order to avoid ad-hoc parameter tunning, we do the
+labeling via search best parameter for the whole trace.
+Then it introduces a problem: for the same trace, we have three settings
+1. best parameters for the whole trace
+2. default parameters for 20% trace + best parameters for the remaining 80% trace
+3. default parameters for the whole trace
+
+We have a hypothesis is that case 1 < case 2 < case 3 in terms of miss ratio, but we find that sometimes case 2 would be worse than case 3, which is counterintuitive.
+
+Then we conducted a typical analysis over `/mnt/cfs/oracleReuse/tencentBlock/tencentBlock.ns4712.oracleGeneral.zst`.
+
+
+When explaining code, always include:
+
+1. **Start with an analogy**: Compare the code to something from everyday life
+2. **Draw a diagram**: Use ASCII art to show the flow, structure, or relationships
+3. **Walk through the code**: Explain step-by-step what happens
+4. **Highlight a gotcha**: What's a common mistake or misconception?
+
+Keep explanations conversational. For complex concepts, use multiple analogies.