Merge "read repair chance should be set to 0 for datetiered strategy"

Juniper · Feb 24, 2017 · c1ee317 · c1ee317
2 parents ce138ae + cfb536f
commit c1ee317
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Showing 2 changed files with 33 additions and 4 deletions.
diff --git a/src/database/cassandra/cql/cql_if.cc b/src/database/cassandra/cql/cql_if.cc
@@ -18,6 +18,7 @@
 #include <base/string_util.h>
 #include <io/event_manager.h>
 #include <database/gendb_if.h>
+#include <database/gendb_constants.h>
 #include <database/cassandra/cql/cql_if.h>
 #include <database/cassandra/cql/cql_if_impl.h>
 #include <database/cassandra/cql/cql_lib_if.h>
@@ -414,6 +415,8 @@ static const char * kQCompactionStrategy(
     "compaction = {'class': "
     "'org.apache.cassandra.db.compaction.%s'}");
 static const std::string kQGCGraceSeconds("gc_grace_seconds = 0");
+static const std::string kQReadRepairChanceDTCS(
+             "read_repair_chance = 0.0");
 
 //
 // Cf2CassCreateTableIfNotExists
@@ -441,8 +444,21 @@ std::string StaticCf2CassCreateTableIfNotExists(const GenDb::NewCf &cf,
     int n(snprintf(cbuf, sizeof(cbuf), kQCompactionStrategy,
        compaction_strategy.c_str()));
     assert(!(n < 0 || n >= (int)sizeof(cbuf)));
-    query << ") WITH " << std::string(cbuf) << " AND " <<
-        kQGCGraceSeconds;
+
+    // The compaction strategy DateTieredCompactionStrategy precludes 
+    // using read repair, because of the way timestamps are checked for 
+    // DTCS compaction.In this case, you must set read_repair_chance to 
+    // zero. For other compaction strategies, read repair should be 
+    // enabled with a read_repair_chance value of 0.2 being typical
+    if (compaction_strategy == 
+        GenDb::g_gendb_constants.DATE_TIERED_COMPACTION_STRATEGY) {
+        query << ") WITH " << std::string(cbuf) << " AND " <<
+            kQReadRepairChanceDTCS << " AND " << kQGCGraceSeconds;
+    } else {
+        query << ") WITH " << std::string(cbuf) << " AND " << 
+            kQGCGraceSeconds;
+    }
+
     return query.str();
 }
 
@@ -503,8 +519,20 @@ std::string DynamicCf2CassCreateTableIfNotExists(const GenDb::NewCf &cf,
     int n(snprintf(cbuf, sizeof(cbuf), kQCompactionStrategy,
        compaction_strategy.c_str()));
     assert(!(n < 0 || n >= (int)sizeof(cbuf)));
-    query << ")) WITH " << std::string(cbuf) << " AND " <<
-        kQGCGraceSeconds;
+
+    // The compaction strategy DateTieredCompactionStrategy precludes
+    // using read repair, because of the way timestamps are checked for
+    // DTCS compaction.In this case, you must set read_repair_chance to
+    // zero. For other compaction strategies, read repair should be
+    // enabled with a read_repair_chance value of 0.2 being typical
+    if (compaction_strategy == 
+        GenDb::g_gendb_constants.DATE_TIERED_COMPACTION_STRATEGY) {
+        query << ")) WITH " << std::string(cbuf) << " AND " <<
+            kQReadRepairChanceDTCS << " AND " << kQGCGraceSeconds;
+    } else {
+        query << ")) WITH " << std::string(cbuf) << " AND " <<
+            kQGCGraceSeconds;
+    }
     return query.str();
 }
 

diff --git a/src/database/cassandra/cql/test/cql_if_test.cc b/src/database/cassandra/cql/test/cql_if_test.cc
@@ -174,6 +174,7 @@ TEST_F(CqlIfTest, DynamicCfCreateTable) {
         "column8, column9, column10, column11, column12)) "
         "WITH compaction = {'class': "
         "'org.apache.cassandra.db.compaction.DateTieredCompactionStrategy'} "
+        "AND read_repair_chance = 0.0 "
         "AND gc_grace_seconds = 0");
     EXPECT_EQ(expected_qstring1, actual_qstring1);
 }