Add some useful information to trooper doc.

site/dev/sheriffing/trooper.md

 Infra Trooper Documentation
 ===========================
 
 ### Contents ###
 
 *   [What does an Infra trooper do?](#what_is_a_trooper)
 *   [View current and upcoming troopers](#view_current_upcoming_troopers)
 *   [How to swap trooper shifts](#how_to_swap)
 *   [Tips for troopers](#tips)
 
@@ skipping 19 matching lines @@
 <a name="how_to_swap"></a>
 How to swap trooper shifts
 --------------------------
 
 If you need to swap shifts with someone (because you are out sick or on vacation), please get approval from the person you want to swap with. Then send an email to skiabot@google.com and cc rmistry@.
 
 
 <a name="tips"></a>
 Tips for troopers
 -----------------
-Add your tips here!
+
+- Make sure you are a member of
+  [MDB group chrome-skia-ninja](https://ganpati.corp.google.com/#Group_Info?name=chrome-skia-ninja@prod.google.com).
+  Valentine passwords and Chrome Golo access are based on membership in this
+  group.
+
+- These alerts generally auto-dismiss once the criteria for the alert is no
+  longer met:
+  - Monitoring alerts, including prober, collectd, and others
+  - Disconnected build slaves
+
+- These alerts generally do not auto-dismiss:
+  - Build slaves that failed a step
+  - Disconnected devices (these are detected as the "wait for device" step failing)

[borenet, 2015/09/03 12:23:05]

No need to add to docs, but it's possible to make these auto-dismiss as well. 
The solution is to periodically check for a subsequent build on the same
buildslave in which the step in question (update_scripts or wait-for-device)
succeeded.

[rmistry, 2015/09/03 12:30:27]

It will be useful to file a tracking bug for this. Eric should probably file it
since he knows the most about it.

[dogben, 2015/09/03 15:40:16]

Added bug link.

+
+- "Failed to execute query" may show a different query than the failing one;
+  dismiss the alert to get a new alert showing the query that is actually
+  failing.

[borenet, 2015/09/03 12:23:05]

More detail: All "failed to execute query" alerts are lumped into a single
alert, which is why the failed query which initially triggered the alert may not
be failing any more but the alert is still active because another query is
failing.

[dogben, 2015/09/03 15:40:16]

Done.

+
+- Where machines are located:
+  - Machine name like "skia-vm-NNN" -> GCE
+  - Machine name ends with "a3", "a4", "m3" -> Chrome Golo
+  - Machine name starts with "skiabot-" -> Chapel Hill lab
+  - Machine name starts with "win8" -> Chapel Hill lab (Windows machine
+    names can't be very long, so the "skiabot-shuttle-" prefix is dropped.)
+  - TODO(borenet): slave11-c3

[borenet, 2015/09/03 12:23:05]

I'm actually not sure where this one is.  This runs our presubmit trybot.

[rmistry, 2015/09/03 12:30:27]

Ben, this is a good question for the chrome-infra IRC channel:
https://comlink.googleplex.com/chrome-infra
(good link to bookmark)

[dogben, 2015/09/03 15:40:16]

Added IRC channel. Updated info on chrome infra based on discussion.

+
+- To log in to a Linux buildbot in GCE, use `gcloud compute default@<machine
+  name>`. Choose the zone listed for the
+  [GCE VM](https://pantheon.corp.google.com/project/31977622648/compute/instances)
+  (or specify it using the `--zone` command-line flag).
+
+- To log in to a Windows buildbot in GCE, use
+  [Chrome RDP Extension](https://chrome.google.com/webstore/detail/chrome-rdp/cbkkbcmdlboombapidmoeolnmdacpkch?hl=en-US)
+  with the
+  [IP address of the GCE VM](https://pantheon.corp.google.com/project/31977622648/compute/instances)
+  shown on the [host info page](https://status.skia.org/hosts) for that bot. The
+  username is chrome-bot and the password can be found on
+  [Valentine](https://valentine.corp.google.com/) as "chrome-bot (Win GCE)".
+
+- To access bots in the Chrome Golo,
+  [follow these instructions](https://chrome-internal.googlesource.com/infra/infra_internal/+/master/doc/ssh.md).
+  - Machine name ends with "a3" or "a4" -> ssh command looks like `ssh
+    build3-a3.chrome`
+  - Machine name ends with "m3" -> ssh command looks like `ssh build5-m3.golo`
+  - For MacOS and Windows bots, you will be prompted for a password, which is
+    stored on [Valentine](https://valentine.corp.google.com/) as "Chrome Golo,
+    Perf, GPU bots - chrome-bot".
+
+- Read over the [SkiaLab documentation](../testing/skialab) for more detail on
+  dealing with device alerts.
+
+- To stop a buildslave for a device, log in to the host for that device, `cd
+  ~/buildbot/<device name>/build/slave; make stop`. To start it again,
+  `TESTING_SLAVENAME=<device name> make start`.

[borenet, 2015/09/03 12:23:05]

This should be <slave name>

[dogben, 2015/09/03 15:40:16]

Done.

+
+- Sometimes on Mac and Linux you have to run
+  `~/skiabot-slave-start-on-boot.sh` after reboot.

[borenet, 2015/09/03 12:23:05]

Don't do this without running `ps aux | grep python` to ensure that neither
buildbot or gclient are running.  Sometimes it's just slow to sync before
launching the buildbot slave scripts.

[dogben, 2015/09/03 15:40:16]

Done.