Merge "Add validation rules about IMPALAD"

doc/source/userdoc/cdh_plugin.rst

@@ -75,7 +75,7 @@ cloudera plugin versions:
     and at least one hbase regionserver.
   + Cluster can't contain hbase regionserver without at least one hbase maser.
 
-In case of 5.3.0 version of Cloudera Plugin there are few extra limitations
+In case of 5.3.0 or 5.4.0 version of Cloudera Plugin there are few extra limitations
 in the cluster topology:
 
   + Cluster can't contain flume without at least one datanode.
@@ -93,3 +93,4 @@ in the cluster topology:
   + Cluster can contain at most one impala statestore.
   + Cluster can't contain impala catalogserver without impala statestore,
     at least one impalad service, at least one datanode, and metastore.
+  + If using Imapala, the daemons must be installed on every datanode.

sahara/plugins/cdh/v5_3_0/validation.py

@@ -205,6 +205,12 @@ def validate_cluster_creating(cluster):
         raise ex.InvalidComponentCountException('IMPALA_STATESTORE',
                                                 _('0 or 1'), iss_count)
     if ics_count == 1:
+        datanodes = set(u.get_instances(cluster, "HDFS_DATANODE"))
+        impalads = set(u.get_instances(cluster, "IMPALAD"))
+        if len(datanodes ^ impalads) > 0:
+            raise ex.InvalidClusterTopology(
+                _("IMPALAD must be installed on every HDFS_DATANODE"))
+
         if iss_count != 1:
             raise ex.RequiredServiceMissingException(
                 'IMPALA_STATESTORE', required_by='IMPALA')

sahara/plugins/cdh/v5_4_0/validation.py

@@ -226,6 +226,12 @@ def validate_cluster_creating(cluster):
         raise ex.InvalidComponentCountException('IMPALA_STATESTORE',
                                                 _('0 or 1'), iss_count)
     if ics_count == 1:
+        datanodes = set(u.get_instances(cluster, "HDFS_DATANODE"))
+        impalads = set(u.get_instances(cluster, "IMPALAD"))
+        if len(datanodes ^ impalads) > 0:
+            raise ex.InvalidClusterTopology(
+                _("IMPALAD must be installed on every HDFS_DATANODE"))
+
         if iss_count != 1:
             raise ex.RequiredServiceMissingException(
                 'IMPALA_STATESTORE', required_by='IMPALA')

sahara/plugins/exceptions.py

@@ -85,6 +85,20 @@ class InvalidComponentCountException(e.SaharaException):
         super(InvalidComponentCountException, self).__init__()
 
 
+class InvalidClusterTopology(e.SaharaException):
+    """Exception indicating another problems in a cluster topology,
+
+    which is different from InvalidComponentCountException and
+    RequiredServiceMissingException.
+    """
+    code = "INVALID_TOPOLOGY"
+    message = _("Cluster has invalid topology: {description}")
+
+    def __init__(self, description):
+        self.message = self.message.format(description=description)
+        super(InvalidClusterTopology, self).__init__()
+
+
 class HadoopProvisionError(e.SaharaException):
     """Exception indicating that cluster provisioning failed.