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+---
+permalink: /presentations/
+title: "Presentations"
+excerpt: "Presentations."
+sitemap: false
+marp: true
+---
+---
+title: "11 Things I Hate About You"
+description: "Talk for LexTalkTech Fall 2023"
+author: "Nyefan"
+keywords: "devops,kubernetes"
+theme: "gaia"
+footer: "LexTalk Tech 2023-10"
+url: "https://nyefan.org/Presentations/2023_Q3_LexTalkTech"
+image: "https://nyefan.org/Presentations/2023_Q3_LexTalkTech/icon.webp"
+---
+<!--Good Evening! <pause for response>-->
+<!--How are we doing tonight? <pause for response>-->
+<!--I only have 15 minutes here, so we're gonna go fast.-->
+<!--This presentation and the presenter notes will be available at presentations.nyefan.org if you want to see it again-->
+<!--The code for this presentation is available at github.com/Nyefan/Presentations-->
+
+---
+## <br />
+# DEVELOPERS
+### <sub><br /></sub>
+<!--Developers! <short pause>-->
+<!--I'm gonna make you think about operations tonight.-->
+<!--Your devops engineers are gonna love me.-->
+<!--<hand to ear> Sorry, it's Site Reliability now?-->
+<!--<smiling, slightly slower, and with satisfaction> Platform Engineering-->
+<!--How many process and operations engineers of different flavors do we have tonight, raise your hands?-->
+<!--You guys already know this, you can go to sleep for the next 13 minutes and 15 seconds-->
+<!--<eat the mic, lower voice conspiratorially> This talk is quarterly, so that's 53 minutes if you come to all 4-->
+<!--Developers, we're gonna talk tonight about a number of action items you can take to make your platform teams' lives a hell of a lot easier and make your software more robust and reliable in the process-->
+<!--Without further ado, here is...-->
+
+---
+## <br />
+# DEVELOPERS
+### <br />
+## 10 Things I Hate About You
+<!--10 Things I Hate About You.-->
+
+---
+## <br />
+# DEVELOPERS
+### &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span style="color:red;">7</span>
+## <span style="color:red;text-decoration:line-through"><span style="color:#455a64">10</span></span><span style="color:red;font-family:monospace;font-size:0.32em;">‸</span>Things I Hate About You
+<!--Well, 7, actually - we don't have time for 10-->
+
+---
+### You don't capture and handle `SIGTERM` and `SIGKILL`
+###### Kubernetes scale down process*
+```rust
+remove pod from the network load balancers
+send SIGTERM to containers in pod
+loop 30 seconds:
+  if processes have exited:
+    delete resources;
+    exit 0;
+  sleep;
+send SIGKILL to containers in pod
+delete resources;
+exit 0;
+```
+###### <span style="font-size:0.5em;right:30px;text-align:right">*simplified; see the [kubernetes pod lifecycle](https://kubernetes.io/docs/concepts/workloads/pods/pod-lifecycle/) for full details</span>
+
+---
+### You use at most once semantics
+###### Example network call scheme
+```rust
+function network_call(data):
+  result = HttpClient.verb(data);
+  if result.ok():
+    return result;
+  else if result.error().status_code not in [config.RETRYABLE_ERROR_CODES]:
+    log.error(result.error().error_code);
+    return result.error();
+  else:
+    return retry(network_call, data)
+```
+###### <span style="font-size:0.5em;right:30px;text-align:right">the `network_call` should be idempotent</span>
+
+---
+### Your retries are too fast
+###### Example retry scheme
+```rust
+function retry(network_call, data):
+  retry_count = 0
+  delay = config.INITIAL_DELAY;
+  while retry_count <= config.MAX_RETRIES:
+    delay = min(
+      config.MAX_DELAY,
+      delay * config.BACKOFF_FACTOR + rng.range(0.0..1.0) * config.JITTER_FACTOR
+    );
+    sleep(delay);
+    if (network_call(data).ok()) break;
+```
+###### <span style="font-size:0.5em;right:30px;text-align:right">the recursive `network_call` won't work, but slides only have 10 lines</span>
+
+---
+### You hard code default config variables
+###### Example configuration variable scheme
+```rust
+ENV = os.environ.get("APPNAME_ENV")
+
+function coalesce(env_var_name, config_var_path):
+  return os.environ.get(env_var_name) or 
+    config.read(config_var_path, f"${ENV}.yaml") or 
+    config.read(config_var_path, "defaults.yaml") or 
+    raise Exception()
+
+DOWNSTREAM_SERVICE_URL = coalesce("APPNAME_DOWNSTREAM_SERVICE_URL", "appname.downstream_service.url")
+RETRIES_INITIAL_DELAY  = coalesce("APPNAME_RETRIES_INITIAL_DELAY", "appname.retries.initial_delay")
+RETRIES_MAX_RETRIES    = coalesce("APPNAME_RETRIES_MAX_RETRIES", "appname.retries.max_retries")
+...
+```
+
+---
+###