WT-3100 test bug: format is weighted to delete, insert, then write operations (#3219)

test/format was weighted to delete, insert, then write operations, which meant that configuring insert=80 might have no effect, if the randomly assigned percentage of delete operations was 95.  Rewrite the code that calculates operation percentages to assign operation percentages
in a random order, add an explicit read percentage instead of making all non-allocated operations default to reads.

3 files changed, 97 insertions, 26 deletions

diff --git a/test/format/config.c b/test/format/config.c
index cf922b5db04..43447c9ba02 100644
--- a/test/format/config.c
+++ b/test/format/config.c
@@ -44,6 +44,7 @@ static void	   config_map_compression(const char *, u_int *);
 static void	   config_map_encryption(const char *, u_int *);
 static void	   config_map_file_type(const char *, u_int *);
 static void	   config_map_isolation(const char *, u_int *);
+static void	   config_pct(void);
 static void	   config_reset(void);
 
 /*
@@ -159,31 +160,19 @@ config_setup(void)
 	config_encryption();
 	config_isolation();
 	config_lrt();
+	config_pct();
 
 	/*
-	 * Periodically, set the delete percentage to 0 so salvage gets run,
-	 * as long as the delete percentage isn't nailed down.
-	 * Don't do it on the first run, all our smoke tests would hit it.
-	 */
-	if (!g.replay && g.run_cnt % 10 == 9 && !config_is_perm("delete_pct"))
-		config_single("delete_pct=0", 0);
-
-	/*
-	 * If this is an LSM run, set the cache size and crank up the insert
-	 * percentage.
+	 * If this is an LSM run, ensure cache size sanity.
+	 * Ensure there is at least 1MB of cache per thread.
 	 */
-	if (DATASOURCE("lsm")) {
-		if (!config_is_perm("cache"))
+	if (!config_is_perm("cache")) {
+		if (DATASOURCE("lsm"))
 			g.c_cache = 30 * g.c_chunk_size;
-
-		if (!config_is_perm("insert_pct"))
-			g.c_insert_pct = mmrand(NULL, 50, 85);
+		if (g.c_cache < g.c_threads)
+			g.c_cache = g.c_threads;
 	}
 
-	/* Ensure there is at least 1MB of cache per thread. */
-	if (!config_is_perm("cache") && g.c_cache < g.c_threads)
-		g.c_cache = g.c_threads;
-
 	/* Give in-memory configuration a final review. */
 	config_in_memory_check();
 
@@ -482,6 +471,83 @@ config_lrt(void)
 }
 
 /*
+ * config_pct --
+ *	Configure operation percentages.
+ */
+static void
+config_pct(void)
+{
+	static struct {
+		const char *name;		/* Operation */
+		uint32_t  *vp;			/* Value store */
+		u_int	   order;		/* Order of assignment */
+	} list[] = {
+#define	CONFIG_DELETE_ENTRY	0
+		{ "delete_pct", &g.c_delete_pct, 0 },
+		{ "insert_pct", &g.c_insert_pct, 0 },
+		{ "read_pct", &g.c_read_pct, 0 },
+		{ "write_pct", &g.c_write_pct, 0 },
+	};
+	u_int i, max_order, max_slot, n, pct;
+
+	/*
+	 * Walk the list of operations, checking for an illegal configuration
+	 * and creating a random order in the list.
+	 */
+	pct = 0;
+	for (i = 0; i < WT_ELEMENTS(list); ++i)
+		if (config_is_perm(list[i].name))
+			pct += *list[i].vp;
+		else
+			list[i].order = mmrand(NULL, 0, 1000);
+	if (pct > 100)
+		testutil_die(EINVAL,
+		    "operation percentages total to more than 100%%");
+
+	/*
+	 * If the delete percentage isn't nailed down, periodically set it to
+	 * 0 so salvage gets run. Don't do it on the first run, all our smoke
+	 * tests would hit it.
+	 */
+	if (!config_is_perm("delete_pct") && !g.replay && g.run_cnt % 10 == 9) {
+		list[CONFIG_DELETE_ENTRY].order = 0;
+		*list[CONFIG_DELETE_ENTRY].vp = 0;
+	}
+
+	/*
+	 * Walk the list, allocating random numbers of operations in a random
+	 * order.
+	 *
+	 * If the "order" field is non-zero, we need to create a value for this
+	 * operation. Find the largest order field in the array; if one non-zero
+	 * order field is found, it's the last entry and gets the remainder of
+	 * the operations.
+	 */
+	for (pct = 100 - pct;;) {
+		for (i = n =
+		    max_order = max_slot = 0; i < WT_ELEMENTS(list); ++i) {
+			if (list[i].order != 0)
+				++n;
+			if (list[i].order > max_order) {
+				max_order = list[i].order;
+				max_slot = i;
+			}
+		}
+		if (n == 0)
+			break;
+		if (n == 1) {
+			*list[max_slot].vp = pct;
+			break;
+		}
+		*list[max_slot].vp = mmrand(NULL, 0, pct);
+		list[max_slot].order = 0;
+		pct -= *list[max_slot].vp;
+	}
+	testutil_assert(g.c_delete_pct +
+	    g.c_insert_pct + g.c_read_pct + g.c_write_pct == 100);
+}
+
+/*
  * config_error --
  *	Display configuration information on error.
  */
diff --git a/test/format/config.h b/test/format/config.h
index e4f7af2e1b2..e3e1e73a786 100644
--- a/test/format/config.h
+++ b/test/format/config.h
@@ -131,7 +131,7 @@ static CONFIG c[] = {
 
 	{ "delete_pct",
 	  "percent operations that are deletes",
-	  0x0, 0, 45, 90, &g.c_delete_pct, NULL },
+	  C_IGNORE, 0, 0, 100, &g.c_delete_pct, NULL },
 
 	{ "dictionary",
 	  "if values are dictionary compressed",		/* 20% */
@@ -171,7 +171,7 @@ static CONFIG c[] = {
 
 	{ "insert_pct",
 	  "percent operations that are inserts",
-	  0x0, 0, 45, 90, &g.c_insert_pct, NULL },
+	  C_IGNORE, 0, 0, 100, &g.c_insert_pct, NULL },
 
 	{ "internal_key_truncation",
 	  "if internal keys are truncated",			/* 95% */
@@ -254,6 +254,14 @@ static CONFIG c[] = {
 	  "quiet run (same as -q)",
 	  C_IGNORE|C_BOOL, 0, 0, 0, &g.c_quiet, NULL },
 
+	{ "read_pct",
+	  "percent operations that are reads",
+	  C_IGNORE, 0, 0, 100, &g.c_read_pct, NULL },
+
+	{ "rebalance",
+	  "rebalance testing",					/* 100% */
+	  C_BOOL, 100, 1, 0, &g.c_rebalance, NULL },
+
 	{ "repeat_data_pct",
 	  "percent duplicate values in row- or var-length column-stores",
 	  0x0, 0, 90, 90, &g.c_repeat_data_pct, NULL },
@@ -270,10 +278,6 @@ static CONFIG c[] = {
 	  "the number of runs",
 	  C_IGNORE, 0, UINT_MAX, UINT_MAX, &g.c_runs, NULL },
 
-	{ "rebalance",
-	  "rebalance testing",					/* 100% */
-	  C_BOOL, 100, 1, 0, &g.c_rebalance, NULL },
-
 	{ "salvage",
 	  "salvage testing",					/* 100% */
 	  C_BOOL, 100, 1, 0, &g.c_salvage, NULL },
@@ -320,7 +324,7 @@ static CONFIG c[] = {
 
 	{ "write_pct",
 	  "percent operations that are writes",
-	  0x0, 0, 90, 90, &g.c_write_pct, NULL },
+	  C_IGNORE, 0, 0, 100, &g.c_write_pct, NULL },
 
 	{ NULL, NULL, 0x0, 0, 0, 0, NULL, NULL }
 };
diff --git a/test/format/format.h b/test/format/format.h
index c1f4875dbb2..6bb44410acc 100644
--- a/test/format/format.h
+++ b/test/format/format.h
@@ -192,6 +192,7 @@ typedef struct {
 	uint32_t c_reverse;
 	uint32_t c_rows;
 	uint32_t c_runs;
+	uint32_t c_read_pct;
 	uint32_t c_rebalance;
 	uint32_t c_salvage;
 	uint32_t c_split_pct;