Fix issues 1200 and 1295, add rocksdb_compact_lzero_now global variab…

…le (facebook#1309)

Summary:
This fixes issue 1295 and has a workaround for issue 1200. facebook#1200
facebook#1295

The fix for issue 1295 is to get the value of the base level from RocksDB rather than assuming that L0 compacts into L1 because L1 might not be the base level when dynamic leveled compaction is used -- in that case the base level can be Ln where n > 1 because L1 isn't needed yet.

There are two workarounds for issue 1200. The hacky one is to sleep for 1 second between requesting memtable flush and L0 -> base_level compaction.

The alternative is to add a new global variable, rocksdb_compact_lzero_now, that when set will request L0 -> base_level compaction. This allows a client to first set rocksdb_force_flush_memtable_now, wait for that to finish, then set rocksdb_compact_lzero_now.

Other changes:
* rocksdb_force_flush_memtable_now default value changed to OFF to match what is done for rocksdb_force_flush_memtable_and_lzero_now and rocksdb_compact_lzero_now
* confirm that the value to which these variables are set can be parsed, that wasn't done for all of them
* don't raise an error when these are set to OFF, that will be a no-op

Note: these variables are triggers, an action is taken when this is done: set global var = ON | true | 1

But these variables always show the value 0 (OFF, false). Their value doesn't change.

Pull Request resolved: facebook#1309

Differential Revision: D45789784

mysql-test/r/mysqld--help-notwin.result

@@ -1975,6 +1975,8 @@ The following options may be given as the first argument:
  (Defaults to on; use --skip-rocksdb-commit-time-batch-for-recovery to disable.)
  --rocksdb-compact-cf=name 
  Compact column family
+ --rocksdb-compact-lzero-now 
+ Compacts all L0 files.
  --rocksdb-compaction-history[=name] 
  Enable or disable ROCKSDB_COMPACTION_HISTORY plugin.
  Possible values are ON, OFF, FORCE (don't start if the
@@ -2147,7 +2149,6 @@ The following options may be given as the first argument:
  --rocksdb-force-flush-memtable-now 
  Forces memstore flush which may block all write requests
  so be careful
- (Defaults to on; use --skip-rocksdb-force-flush-memtable-now to disable.)
  --rocksdb-force-index-records-in-range=# 
  Used to override the result of records_in_range() when
  FORCE INDEX is used.
@@ -3633,6 +3634,7 @@ rocksdb-column-default-value-as-expression TRUE
 rocksdb-commit-in-the-middle FALSE
 rocksdb-commit-time-batch-for-recovery TRUE
 rocksdb-compact-cf 
+rocksdb-compact-lzero-now FALSE
 rocksdb-compaction-history ON
 rocksdb-compaction-readahead-size 2097152
 rocksdb-compaction-sequential-deletes 0
@@ -3686,7 +3688,7 @@ rocksdb-flush-log-at-trx-commit 1
 rocksdb-force-compute-memtable-stats TRUE
 rocksdb-force-compute-memtable-stats-cachetime 60000000
 rocksdb-force-flush-memtable-and-lzero-now FALSE
-rocksdb-force-flush-memtable-now TRUE
+rocksdb-force-flush-memtable-now FALSE
 rocksdb-force-index-records-in-range 0
 rocksdb-global-info ON
 rocksdb-ignore-unknown-options TRUE

mysql-test/suite/rocksdb/r/rocksdb.result

@@ -936,6 +936,7 @@ rocksdb_column_default_value_as_expression	ON
 rocksdb_commit_in_the_middle	OFF
 rocksdb_commit_time_batch_for_recovery	ON
 rocksdb_compact_cf	
+rocksdb_compact_lzero_now	OFF
 rocksdb_compaction_readahead_size	2097152
 rocksdb_compaction_sequential_deletes	0
 rocksdb_compaction_sequential_deletes_count_sd	OFF
@@ -984,7 +985,7 @@ rocksdb_flush_log_at_trx_commit	1
 rocksdb_force_compute_memtable_stats	ON
 rocksdb_force_compute_memtable_stats_cachetime	0
 rocksdb_force_flush_memtable_and_lzero_now	OFF
-rocksdb_force_flush_memtable_now	ON
+rocksdb_force_flush_memtable_now	OFF
 rocksdb_force_index_records_in_range	0
 rocksdb_ignore_unknown_options	ON
 rocksdb_index_type	kBinarySearch

mysql-test/suite/rocksdb_sys_vars/r/rocksdb_compact_lzero_now_basic.result

@@ -0,0 +1,83 @@
+CREATE TABLE valid_values (value varchar(255)) ENGINE=myisam;
+INSERT INTO valid_values VALUES(1);
+INSERT INTO valid_values VALUES('on');
+INSERT INTO valid_values VALUES('true');
+INSERT INTO valid_values VALUES(0);
+INSERT INTO valid_values VALUES('off');
+INSERT INTO valid_values VALUES('false');
+CREATE TABLE invalid_values (value varchar(255)) ENGINE=myisam;
+SET @start_global_value = @@global.ROCKSDB_COMPACT_LZERO_NOW;
+SELECT @start_global_value;
+@start_global_value
+0
+'# Setting to valid values in global scope#'
+"Trying to set variable @@global.ROCKSDB_COMPACT_LZERO_NOW to 1"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW   = 1;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Trying to set variable @@global.ROCKSDB_COMPACT_LZERO_NOW to on"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW   = on;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Trying to set variable @@global.ROCKSDB_COMPACT_LZERO_NOW to true"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW   = true;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Trying to set variable @@global.ROCKSDB_COMPACT_LZERO_NOW to 0"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW   = 0;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Trying to set variable @@global.ROCKSDB_COMPACT_LZERO_NOW to off"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW   = off;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Trying to set variable @@global.ROCKSDB_COMPACT_LZERO_NOW to false"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW   = false;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+"Trying to set variable @@session.ROCKSDB_COMPACT_LZERO_NOW to 444. It should fail because it is not session."
+SET @@session.ROCKSDB_COMPACT_LZERO_NOW   = 444;
+ERROR HY000: Variable 'rocksdb_compact_lzero_now' is a GLOBAL variable and should be set with SET GLOBAL
+'# Testing with invalid values in global scope #'
+SET @@global.ROCKSDB_COMPACT_LZERO_NOW = @start_global_value;
+SELECT @@global.ROCKSDB_COMPACT_LZERO_NOW;
+@@global.ROCKSDB_COMPACT_LZERO_NOW
+0
+DROP TABLE valid_values;
+DROP TABLE invalid_values;

mysql-test/suite/rocksdb_sys_vars/r/rocksdb_force_flush_memtable_and_lzero_now_basic.result

@@ -1,7 +1,10 @@
 CREATE TABLE valid_values (value varchar(255)) ENGINE=myisam;
 INSERT INTO valid_values VALUES(1);
-INSERT INTO valid_values VALUES(0);
 INSERT INTO valid_values VALUES('on');
+INSERT INTO valid_values VALUES('true');
+INSERT INTO valid_values VALUES(0);
+INSERT INTO valid_values VALUES('off');
+INSERT INTO valid_values VALUES('false');
 CREATE TABLE invalid_values (value varchar(255)) ENGINE=myisam;
 SET @start_global_value = @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW;
 SELECT @start_global_value;
@@ -18,6 +21,26 @@ SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW = DEFAULT;
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW
 0
+"Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW to on"
+SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW   = on;
+SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW;
+@@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW;
+@@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW
+0
+"Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW to true"
+SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW   = true;
+SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW;
+@@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW;
+@@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW
+0
 "Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW to 0"
 SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW   = 0;
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW;
@@ -28,8 +51,18 @@ SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW = DEFAULT;
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW
 0
-"Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW to on"
-SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW   = on;
+"Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW to off"
+SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW   = off;
+SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW;
+@@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW;
+@@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW
+0
+"Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW to false"
+SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW   = false;
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_AND_LZERO_NOW
 0

mysql-test/suite/rocksdb_sys_vars/r/rocksdb_force_flush_memtable_now_basic.result

@@ -2,70 +2,82 @@ CREATE TABLE valid_values (value varchar(255)) ENGINE=myisam;
 INSERT INTO valid_values VALUES(1);
 INSERT INTO valid_values VALUES('on');
 INSERT INTO valid_values VALUES('true');
+INSERT INTO valid_values VALUES(0);
+INSERT INTO valid_values VALUES('off');
+INSERT INTO valid_values VALUES('false');
 CREATE TABLE invalid_values (value varchar(255)) ENGINE=myisam;
-INSERT INTO invalid_values VALUES(0);
-INSERT INTO invalid_values VALUES('off');
-INSERT INTO invalid_values VALUES('false');
 SET @start_global_value = @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
 SELECT @start_global_value;
 @start_global_value
-1
+0
 '# Setting to valid values in global scope#'
 "Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW to 1"
 SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW   = 1;
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
-1
+0
 "Setting the global scope variable back to default"
 SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW = DEFAULT;
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
-1
+0
 "Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW to on"
 SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW   = on;
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
-1
+0
 "Setting the global scope variable back to default"
 SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW = DEFAULT;
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
-1
+0
 "Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW to true"
 SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW   = true;
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
-1
+0
 "Setting the global scope variable back to default"
 SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW = DEFAULT;
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
-1
-"Trying to set variable @@session.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW to 444. It should fail because it is not session."
-SET @@session.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW   = 444;
-ERROR HY000: Variable 'rocksdb_force_flush_memtable_now' is a GLOBAL variable and should be set with SET GLOBAL
-'# Testing with invalid values in global scope #'
+0
 "Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW to 0"
 SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW   = 0;
-Got one of the listed errors
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
-1
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
+@@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
+0
 "Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW to off"
 SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW   = off;
-Got one of the listed errors
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
-1
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
+@@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
+0
 "Trying to set variable @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW to false"
 SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW   = false;
-Got one of the listed errors
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
-1
+0
+"Setting the global scope variable back to default"
+SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW = DEFAULT;
+SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
+@@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
+0
+"Trying to set variable @@session.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW to 444. It should fail because it is not session."
+SET @@session.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW   = 444;
+ERROR HY000: Variable 'rocksdb_force_flush_memtable_now' is a GLOBAL variable and should be set with SET GLOBAL
+'# Testing with invalid values in global scope #'
 SET @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW = @start_global_value;
 SELECT @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW;
 @@global.ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
-1
+0
 DROP TABLE valid_values;
 DROP TABLE invalid_values;

mysql-test/suite/rocksdb_sys_vars/t/rocksdb_compact_lzero_now_basic.test

@@ -0,0 +1,20 @@
+--source include/have_rocksdb.inc
+
+CREATE TABLE valid_values (value varchar(255)) ENGINE=myisam;
+INSERT INTO valid_values VALUES(1);
+INSERT INTO valid_values VALUES('on');
+INSERT INTO valid_values VALUES('true');
+INSERT INTO valid_values VALUES(0);
+INSERT INTO valid_values VALUES('off');
+INSERT INTO valid_values VALUES('false');
+
+CREATE TABLE invalid_values (value varchar(255)) ENGINE=myisam;
+
+--let $sys_var=ROCKSDB_COMPACT_LZERO_NOW
+--let $read_only=0
+--let $session=0
+--let $sticky=1
+--source ../include/rocksdb_sys_var.inc
+
+DROP TABLE valid_values;
+DROP TABLE invalid_values;

mysql-test/suite/rocksdb_sys_vars/t/rocksdb_force_flush_memtable_and_lzero_now_basic.test

@@ -2,8 +2,11 @@
 
 CREATE TABLE valid_values (value varchar(255)) ENGINE=myisam;
 INSERT INTO valid_values VALUES(1);
-INSERT INTO valid_values VALUES(0);
 INSERT INTO valid_values VALUES('on');
+INSERT INTO valid_values VALUES('true');
+INSERT INTO valid_values VALUES(0);
+INSERT INTO valid_values VALUES('off');
+INSERT INTO valid_values VALUES('false');
 
 CREATE TABLE invalid_values (value varchar(255)) ENGINE=myisam;
 

mysql-test/suite/rocksdb_sys_vars/t/rocksdb_force_flush_memtable_now_basic.test

@@ -4,11 +4,11 @@ CREATE TABLE valid_values (value varchar(255)) ENGINE=myisam;
 INSERT INTO valid_values VALUES(1);
 INSERT INTO valid_values VALUES('on');
 INSERT INTO valid_values VALUES('true');
+INSERT INTO valid_values VALUES(0);
+INSERT INTO valid_values VALUES('off');
+INSERT INTO valid_values VALUES('false');
 
 CREATE TABLE invalid_values (value varchar(255)) ENGINE=myisam;
-INSERT INTO invalid_values VALUES(0);
-INSERT INTO invalid_values VALUES('off');
-INSERT INTO invalid_values VALUES('false');
 
 --let $sys_var=ROCKSDB_FORCE_FLUSH_MEMTABLE_NOW
 --let $read_only=0