Merge pull request metabase#7617 from metabase/let-the-sparks-fly

Separate SparkSQL dependencies [ci drivers]

bin/ci

@@ -129,6 +129,10 @@ install-presto() {
 }
 
 install-sparksql() {
+    # first, download the Spark Deps JAR and put it in the plugins/ dir
+    wget --output-document=plugins/spark-deps.jar https://s3.amazonaws.com/sparksql-deps/metabase-sparksql-deps-1.2.1.spark2-standalone.jar
+
+    # next, download Spark and run it
     spark_version='2.1.1' # Java 7 support was removed in Spark 2.2 so don't upgrade until we upgrade CI
     hadoop_version='2.7'
 

docs/administration-guide/01-managing-databases.md

@@ -24,6 +24,7 @@ Now you’ll see a list of your databases. To connect another database to Metaba
 * [Vertica](databases/vertica.md)
 * Presto
 * Google Analytics
+* [SparkSQL](databases/spark.md)
 
 To add a database, you'll need its connection information.
 

docs/administration-guide/databases/spark.md

@@ -0,0 +1,50 @@
+## Working with SparkSQL in Metabase
+
+Starting in v0.29.0, Metabase provides a driver for connecting to SparkSQL databases. Under the hood, Metabase uses SparkSQL's
+JDBC driver and other dependencies; due to the sheer size of this dependency, we can't include it as part of Metabase. Luckily, downloading it yourself
+ and making it available to Metabase is straightforward and only takes a few minutes.
+
+### Downloading the SparkSQL JDBC Driver JAR
+
+You can download the required dependencies [here](https://s3.amazonaws.com/sparksql-deps/metabase-sparksql-deps-1.2.1.spark2-standalone.jar).
+
+### Adding the SparkSQL JDBC Driver JAR to the Metabase Plugins Directory
+
+Metabase will automatically make the SparkSQL driver available if it finds the SparkSQL dependencies JAR in the Metabase plugins
+directory when it starts up. All you need to do is create the directory, move the JAR you just downloaded into it, and restart
+Metabase.
+
+By default, the plugins directory is called `plugins`, and lives in the same directory as the Metabase JAR.
+
+For example, if you're running Metabase from a directory called `/app/`, you should move the SparkSQL dependencies JAR to
+`/app/plugins/`:
+
+```bash
+# example directory structure for running Metabase with SparkSQL support
+/app/metabase.jar
+/app/plugins/metabase-sparksql-deps-1.2.1.spark2-standalone.jar
+```
+
+If you're running Metabase from the Mac App, the plugins directory defaults to `~/Library/Application Support/Metabase/Plugins/`:
+
+```bash
+# example directory structure for running Metabase Mac App with SparkSQL support
+/Users/camsaul/Library/Application Support/Metabase/Plugins/metabase-sparksql-deps-1.2.1.spark2-standalone.jar
+```
+
+Finally, you can choose a custom plugins directory if the default doesn't suit your needs by setting the environment variable
+`MB_PLUGINS_DIR`.
+
+
+### Enabling Plugins on Java 9
+
+Java 9 disables dynamically adding JARs to the Java classpath by default for security reasons. For the time being, we recommend you
+run Metabase with Java 8 when using the SparkSQL driver.
+
+You may be able to get Java 9 to work by passing an extra JVM option:
+
+```bash
+java --add-opens=java.base/java.net=ALL-UNNAMED -jar metabase.jar
+```
+
+The default Docker images already include this option.

project.clj

@@ -92,16 +92,6 @@
                  [org.liquibase/liquibase-core "3.5.3"]               ; migration management (Java lib)
                  [org.postgresql/postgresql "42.1.4.jre7"]            ; Postgres driver
                  [org.slf4j/slf4j-log4j12 "1.7.25"]                   ; abstraction for logging frameworks -- allows end user to plug in desired logging framework at deployment time
-                 [org.spark-project.hive/hive-jdbc "1.2.1.spark2"     ; JDBC Driver for Apache Spark
-                  :exclusions [org.apache.curator/curator-framework
-                               org.apache.curator/curator-recipes
-                               org.apache.thrift/libfb303
-                               org.apache.zookeeper/zookeeper
-                               org.eclipse.jetty.aggregate/jetty-all
-                               org.spark-project.hive/hive-common
-                               org.spark-project.hive/hive-metastore
-                               org.spark-project.hive/hive-serde
-                               org.spark-project.hive/hive-shims]]
                  [org.tcrawley/dynapath "0.2.5"]                      ; Dynamically add Jars (e.g. Oracle or Vertica) to classpath
                  [org.xerial/sqlite-jdbc "3.21.0.1"]                  ; SQLite driver
                  [org.yaml/snakeyaml "1.18"]                          ; YAML parser (required by liquibase)
@@ -164,10 +154,7 @@
                    :env {:mb-run-mode "dev"}
                    :jvm-opts ["-Dlogfile.path=target/log"]
                    ;; Log appender class needs to be compiled for log4j to use it,
-                   ;; classes for fixed Hive driver in must be compiled for tests
-                   :aot [metabase.logger
-                         metabase.driver.FixedHiveConnection
-                         metabase.driver.FixedHiveDriver]}
+                   :aot [metabase.logger]}
              :ci {:jvm-opts ["-Xmx3g"]}
              :reflection-warnings {:global-vars {*warn-on-reflection* true}} ; run `lein check-reflection-warnings` to check for reflection warnings
              :expectations {:injections [(require 'metabase.test-setup  ; for test setup stuff

src/metabase/driver/sparksql.clj

@@ -3,6 +3,7 @@
              [set :as set]
              [string :as s]]
             [clojure.java.jdbc :as jdbc]
+            [clojure.tools.logging :as log]
             [honeysql
              [core :as hsql]
              [helpers :as h]]
@@ -15,7 +16,8 @@
              [hive-like :as hive-like]]
             [metabase.driver.generic-sql.query-processor :as sqlqp]
             [metabase.query-processor.util :as qputil]
-            [metabase.util.honeysql-extensions :as hx])
+            [metabase.util.honeysql-extensions :as hx]
+            [puppetlabs.i18n.core :refer [trs]])
   (:import clojure.lang.Reflector
            java.sql.DriverManager
            metabase.query_processor.interface.Field))
@@ -94,23 +96,6 @@
   [{:keys [host port db jdbc-flags]
     :or   {host "localhost", port 10000, db "", jdbc-flags ""}
     :as   opts}]
-  ;; manually register our FixedHiveDriver with java.sql.DriverManager and make sure it's the only driver returned for
-  ;; jdbc:hive2, since we do not want to use the driver registered by the super class of our FixedHiveDriver.
-  ;;
-  ;; Class/forName and invokeConstructor is required to make this compile, but it may be possible to solve this with
-  ;; the right project.clj magic
-  (DriverManager/registerDriver
-   (Reflector/invokeConstructor
-    (Class/forName "metabase.driver.FixedHiveDriver")
-    (into-array [])))
-  (loop []
-    (when-let [driver (try
-                        (DriverManager/getDriver "jdbc:hive2://localhost:10000")
-                        (catch java.sql.SQLException _
-                          nil))]
-      (when-not (instance? (Class/forName "metabase.driver.FixedHiveDriver") driver)
-        (DriverManager/deregisterDriver driver)
-        (recur))))
   (merge {:classname   "metabase.driver.FixedHiveDriver"
           :subprotocol "hive2"
           :subname     (str "//" host ":" port "/" db jdbc-flags)}
@@ -223,7 +208,39 @@
           :string-length-fn          (u/drop-first-arg hive-like/string-length-fn)
           :unix-timestamp->timestamp (u/drop-first-arg hive-like/unix-timestamp->timestamp)}))
 
+(defn- register-hive-jdbc-driver! [& {:keys [remaining-tries], :or {remaining-tries 5}}]
+  ;; manually register our FixedHiveDriver with java.sql.DriverManager
+  (DriverManager/registerDriver
+   (Reflector/invokeConstructor
+    (Class/forName "metabase.driver.FixedHiveDriver")
+    (into-array [])))
+  ;; now make sure it's the only driver returned
+  ;; for jdbc:hive2, since we do not want to use the driver registered by the super class of our FixedHiveDriver.
+  (when-let [driver (u/ignore-exceptions
+                      (DriverManager/getDriver "jdbc:hive2://localhost:10000"))]
+    (let [registered? (instance? (Class/forName "metabase.driver.FixedHiveDriver") driver)]
+      (cond
+        registered?
+        true
+
+        ;; if it's not the registered driver, deregister the current driver (if applicable) and try a couple more times
+        ;; before giving up :(
+        (and (not registered?)
+             (> remaining-tries 0))
+        (do
+          (when driver
+            (DriverManager/deregisterDriver driver))
+          (recur {:remaining-tries (dec remaining-tries)}))
+
+        :else
+        (log/error
+         (trs "Error: metabase.driver.FixedHiveDriver is registered, but JDBC does not seem to be using it."))))))
+
 (defn -init-driver
-  "Register the SparkSQL driver."
+  "Register the SparkSQL driver if the SparkSQL dependencies are available."
   []
-  (driver/register-driver! :sparksql (SparkSQLDriver.)))
+  (when (u/ignore-exceptions (Class/forName "metabase.driver.FixedHiveDriver"))
+    (log/info (trs "Found metabase.driver.FixedHiveDriver."))
+    (when (u/ignore-exceptions (register-hive-jdbc-driver!))
+      (log/info (trs "Successfully registered metabase.driver.FixedHiveDriver with JDBC."))
+      (driver/register-driver! :sparksql (SparkSQLDriver.)))))