Perf server initial documentation; mostly placeholder now.

perf/server/DESIGN.md

+DESIGN
+======
+
+
+Overview
+--------
+Provides interactive dashboard for Skia performance data.
+
+
+Architecture
+------------
+
+Perf Stats Database
+-------------------
+
+Annotations Database
+--------------------
+
+A Cloud SQL (a cloud version of MySQL) database is used to keep information on Skia git revisions and their corresponding annotations. The database will be updated when users add/edit/delete annotations via the dashboard UI.
+
+All passwords for MySQL are stored in valentine (search "skia perf").
+
+To connect to the database from authorized network (including skia-perf-b GCE):
+
+    $ mysql -h 173.194.104.24 -u root -p
+
+Initial setup of the database, the users, and the tables:
+
+    CREATE DATABASE skia;
+    USE skia;
+    CREATE USER 'readonly'@'%' IDENTIFIED BY <password in valentine>;
+    GRANT SELECT ON *.* TO 'readonly'@'%';
+    CREATE USER 'readwrite'@'%' IDENTIFIED BY <password in valentine>;
+    GRANT SELECT, DELETE, UPDATE, INSERT ON *.* TO 'readwrite'@'%';
+
+    // Table for storing annotations.
+    CREATE TABLE notes (id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, notes VARCHAR(200), UNIQUE INDEX (id));
+
+    // Table for storing git revision information.
+    CREATE TABLE githash (ts INT NOT NULL PRIMARY KEY, gitnumber INT NOT NULL, githash VARCHAR(40) NOT NULL, author VARCHAR(40) NOT NULL, message VARCHAR(200) NOT NULL, UNIQUE INDEX (ts));
+
+    // Table for mapping revisions and annotations. This support many-to-many
+    // mapping.
+    CREATE TABLE githashnotes (ts INT NOT NULL, id INT NOT NULL, FOREIGN KEY (ts) REFERENCES githash(ts), FOREIGN KEY (id) REFERENCES notes(id), UNIQUE INDEX (ts, id));
+
+Password for the database will be stored in the metadata instance. To see the current password stored in metadata and the fingerprint:
+
+    gcutil --project=google.com:skia-buildbots getinstance skia-perf-b
+
+To set the mysql password that webtry is to use:
+
+    gcutil --project=google.com:skia-buildbots setinstancemetadata skia-perf-b --metadata=readonly:[password-from-valentine] --metadata=readwrite:[password-from-valentine] --fingerprint=[the metadata fingerprint]
+
+Installation
+------------
+See the README file.