Work in progress changes for scalable segmented global deduplication.

Allow user-specified environment setting to control in-memory index size.

main.c

@@ -677,7 +677,7 @@ start_decompress(const char *filename, const char *to_filename)
 	int uncompfd = -1, err, np, bail;
 	int nprocs = 1, thread = 0, level;
 	unsigned int i;
-	short version, flags;
+	unsigned short version, flags;
 	int64_t chunksize, compressed_chunksize;
 	struct cmp_data **dary, *tdat;
 	pthread_t writer_thr;
@@ -1644,7 +1644,7 @@ start_compress(const char *filename, uint64_t chunksize, int level)
 	char to_filename[MAXPATHLEN];
 	uint64_t compressed_chunksize, n_chunksize, file_offset;
 	int64_t rbytes, rabin_count;
-	short version, flags;
+	unsigned short version, flags;
 	struct stat sbuf;
 	int compfd = -1, uncompfd = -1, err;
 	int thread, bail, single_chunk;
@@ -1655,21 +1655,9 @@ start_compress(const char *filename, uint64_t chunksize, int level)
 	dedupe_context_t *rctx;
 	algo_props_t props;
 
-	/*
-	 * Compressed buffer size must include zlib/dedup scratch space and
-	 * chunk header space.
-	 * See http://www.zlib.net/manual.html#compress2
-	 * 
-	 * We do this unconditionally whether user mentioned zlib or not
-	 * to keep it simple. While zlib scratch space is only needed at
-	 * runtime, chunk header is stored in the file.
-	 *
-	 * See start_decompress() routine for details of chunk header.
-	 * We also keep extra 8-byte space for the last chunk's size.
-	 */
-	compressed_chunksize = chunksize + CHUNK_HDR_SZ + zlib_buf_extra(chunksize);
 	init_algo_props(&props);
 	props.cksum = cksum;
+	props.buf_extra = 0;
 	cread_buf = NULL;
 
 	if (_props_func) {
@@ -1757,9 +1745,6 @@ start_compress(const char *filename, uint64_t chunksize, int level)
 	thread = 0;
 	single_chunk = 0;
 	rctx = NULL;
-	slab_cache_add(chunksize);
-	slab_cache_add(compressed_chunksize);
-	slab_cache_add(sizeof (struct cmp_data));
 
 	nprocs = sysconf(_SC_NPROCESSORS_ONLN);
 	if (nthreads > 0 && nthreads < nprocs)
@@ -1798,6 +1783,18 @@ start_compress(const char *filename, uint64_t chunksize, int level)
 			single_chunk = 1;
 			props.is_single_chunk = 1;
 			flags |= FLAG_SINGLE_CHUNK;
+
+			/*
+			 * Switch to simple Deduplication if global is enabled.
+			 */
+			if (enable_rabin_global) {
+				unsigned short flg;
+				enable_rabin_scan = 1;
+				enable_rabin_global = 0;
+				dedupe_flag = RABIN_DEDUPE_SEGMENTED;
+				flg = FLAG_DEDUP_FIXED;
+				flags &= ~flg;
+			}
 		} else {
 			if (nthreads == 0 || nthreads > sbuf.st_size / chunksize) {
 				nthreads = sbuf.st_size / chunksize;
@@ -1870,6 +1867,38 @@ start_compress(const char *filename, uint64_t chunksize, int level)
 		strcpy(tmpdir, tmp);
 	}
 
+	/*
+	 * Compressed buffer size must include zlib/dedup scratch space and
+	 * chunk header space.
+	 * See http://www.zlib.net/manual.html#compress2
+	 * 
+	 * We do this unconditionally whether user mentioned zlib or not
+	 * to keep it simple. While zlib scratch space is only needed at
+	 * runtime, chunk header is stored in the file.
+	 *
+	 * See start_decompress() routine for details of chunk header.
+	 * We also keep extra 8-byte space for the last chunk's size.
+	 */
+	compressed_chunksize = chunksize + CHUNK_HDR_SZ + zlib_buf_extra(chunksize);
+	if (chunksize + props.buf_extra > compressed_chunksize) {
+		compressed_chunksize += (chunksize + props.buf_extra - 
+		    compressed_chunksize);
+	}
+
+	if (enable_rabin_scan || enable_fixed_scan || enable_rabin_global) {
+		/* Additional scratch space for dedup arrays. */
+		if (chunksize + dedupe_buf_extra(chunksize, 0, algo, enable_delta_encode)
+		    > compressed_chunksize) {
+			compressed_chunksize += (chunksize +
+			    dedupe_buf_extra(chunksize, 0, algo, enable_delta_encode)) -
+			    compressed_chunksize;
+		}
+	}
+
+	slab_cache_add(chunksize);
+	slab_cache_add(compressed_chunksize);
+	slab_cache_add(sizeof (struct cmp_data));
+
 	if (encrypt_type)
 		flags |= encrypt_type;
 

rabin/global/db.c

@@ -88,17 +88,18 @@ static cleanup_indx(index_t *indx)
 	}
 }
 
-#define	MEM_PER_UNIT ( (hash_entry_size + sizeof (hash_entry_t *) + \
+#define	MEM_PER_UNIT(ent_sz) ( (ent_sz + sizeof (hash_entry_t *) + \
 		(sizeof (hash_entry_t *)) / 2) + sizeof (hash_entry_t **) )
+#define	MEM_REQD(hslots, ent_sz) (hslots * MEM_PER_UNIT(ent_sz))
+#define	SLOTS_FOR_MEM(memlimit, ent_sz) (memlimit / MEM_PER_UNIT(ent_sz) - 5)
 
-archive_config_t *
+int
-init_global_db_s(char *path, char *tmppath, uint32_t chunksize, uint64_t user_chunk_sz,
+setup_db_config_s(archive_config_t *cfg, uint32_t chunksize, uint64_t *user_chunk_sz,
-		 int pct_interval, const char *algo, cksum_t ck, cksum_t ck_sim,
+		 int *pct_interval, const char *algo, cksum_t ck, cksum_t ck_sim,
-		 size_t file_sz, size_t memlimit, int nthreads)
+		 size_t file_sz, uint32_t *hash_slots, int *hash_entry_size,
+		 uint32_t *intervals, uint64_t *memreqd, size_t memlimit)
 {
-	archive_config_t *cfg;
+	int rv, set_user;
-	int rv;
-	float diff;
 
 	/*
 	 * file_sz = 0 and pct_interval = 0 means we are in pipe mode and want a simple
@@ -106,54 +107,92 @@ init_global_db_s(char *path, char *tmppath, uint32_t chunksize, uint64_t user_ch
 	 * for the simple index.
 	 * 
 	 * If file_sz != 0 but pct_interval = 0 then we need to create a simple index
-	 * sized for the given file.
+	 * sized for the given file. If the available memory is not sufficient for a full
+	 * index and required index size is 1.25x of availble mem then switch to a
+	 * segmented index.
 	 * 
-	 * If file_sz = 0 and pct_interval = 100 then we are in pipe mode and want a segmented
+	 * If file_sz != 0 and pct_interval != 0 then we explicitly want to create a segmented
+	 * index. This option is auto-selected to support the previous behavior.
+	 * 
+	 * If file_sz = 0 and pct_interval != 0 then we are in pipe mode and want a segmented
 	 * index. This is typically for WAN deduplication of large data transfers.
 	 */
-	if (file_sz == 0 && pct_interval == 0)
+	if (file_sz == 0 && *pct_interval == 0)
-		pct_interval = 100;
+		*pct_interval = 100;
+	set_user = 0;
 
-	cfg = calloc(1, sizeof (archive_config_t));
+set_cfg:
-	rv = set_config_s(cfg, algo, ck, ck_sim, chunksize, file_sz, user_chunk_sz, pct_interval);
+	rv = set_config_s(cfg, algo, ck, ck_sim, chunksize, file_sz, *user_chunk_sz, *pct_interval);
 
 	if (cfg->dedupe_mode == MODE_SIMPLE) {
-		if (pct_interval != 100)
+		if (*pct_interval != 100)
-			pct_interval = 0;
+			*pct_interval = 0;
 		cfg->pct_interval = 0;
 	}
 
-	if (path != NULL) {
+	/*
-		fprintf(stderr, "Disk based index not yet implemented.\n");
+	 * Adjust user_chunk_sz if this is the second try.
-		free(cfg);
+	 */
-		return (NULL);
+	if (set_user) {
+		if (*user_chunk_sz < cfg->segment_sz_bytes) {
+			*user_chunk_sz = cfg->segment_sz_bytes;
 		} else {
+			*user_chunk_sz = (*user_chunk_sz / cfg->segment_sz_bytes) * cfg->segment_sz_bytes;
+		}
+	}
+
+	// Compute total hashtable entries first
+	*hash_entry_size = sizeof (hash_entry_t) + cfg->similarity_cksum_sz - 1;
+	if (*pct_interval == 0) {
+		*intervals = 1;
+		*hash_slots = file_sz / cfg->chunk_sz_bytes + 1;
+
+	} else if (*pct_interval == 100) {
+		*intervals = 1;
+		*hash_slots = SLOTS_FOR_MEM(memlimit, *hash_entry_size);
+		*pct_interval = 0;
+	} else {
+		*intervals = 100 / *pct_interval - 1;
+		*hash_slots = file_sz / cfg->segment_sz_bytes + 1;
+		*hash_slots *= *intervals;
+	}
+
+	// Compute memory required to hold all hash entries assuming worst case 50%
+	// occupancy.
+	*memreqd = MEM_REQD(*hash_slots, *hash_entry_size);
+
+	if (*memreqd > (memlimit + (memlimit >> 2)) && cfg->dedupe_mode == MODE_SIMPLE &&
+	    *pct_interval == 0) {
+		*pct_interval = DEFAULT_PCT_INTERVAL;
+		set_user = 1;
+		goto set_cfg;
+	}
+	return (rv);
+}
+
+archive_config_t *
+init_global_db_s(char *path, char *tmppath, uint32_t chunksize, uint64_t user_chunk_sz,
+		 int pct_interval, const char *algo, cksum_t ck, cksum_t ck_sim,
+		 size_t file_sz, size_t memlimit, int nthreads)
+{
+	archive_config_t *cfg;
+	int rv, orig_pct;
+	float diff;
 	uint32_t hash_slots, intervals, i;
 	uint64_t memreqd;
 	int hash_entry_size;
 	index_t *indx;
 
-		hash_entry_size = sizeof (hash_entry_t) + cfg->similarity_cksum_sz - 1;
+	if (path != NULL) {
-
+		fprintf(stderr, "Disk based index not yet implemented.\n");
-		// Compute total hashtable entries first
+		return (NULL);
-		if (pct_interval == 0) {
-			intervals = 1;
-			hash_slots = file_sz / cfg->chunk_sz_bytes + 1;
-
-		} else if (pct_interval == 100) {
-			intervals = 1;
-			hash_slots = memlimit / MEM_PER_UNIT - 5;
-			pct_interval = 0;
-		} else {
-			intervals = 100 / pct_interval - 1;
-			hash_slots = file_sz / cfg->segment_sz_bytes + 1;
-			hash_slots *= intervals;
 	}
+	orig_pct = pct_interval;
+	cfg = calloc(1, sizeof (archive_config_t));
 	
-		// Compute memory required to hold all hash entries assuming worst case 50%
-		// occupancy.
-		memreqd = hash_slots * MEM_PER_UNIT;
 	diff = (float)pct_interval / 100.0;
+	rv = setup_db_config_s(cfg, chunksize, &user_chunk_sz, &pct_interval, algo, ck, ck_sim,
+		 file_sz, &hash_slots, &hash_entry_size, &intervals, &memreqd, memlimit);
 
 	// Reduce hash_slots to remain within memlimit
 	while (memreqd > memlimit) {
@@ -162,7 +201,7 @@ init_global_db_s(char *path, char *tmppath, uint32_t chunksize, uint64_t user_ch
 		} else {
 			hash_slots -= (hash_slots * diff);
 		}
-			memreqd = hash_slots * MEM_PER_UNIT;
+		memreqd = hash_slots * MEM_PER_UNIT(hash_entry_size);
 	}
 
 	// Now create as many hash tables as there are similarity match intervals
@@ -203,13 +242,11 @@ init_global_db_s(char *path, char *tmppath, uint32_t chunksize, uint64_t user_ch
 			free(cfg);
 			return (NULL);
 		}
-
 			for (i = 0; i < nthreads; i++) {
 			cfg->seg_fd_r[i] = open(cfg->rootdir, O_RDONLY);
 		}
 	}
 	cfg->dbdata = indx;
-	}
 	return (cfg);
 }
 

rabin/global/db.h

@@ -42,6 +42,10 @@ typedef struct _hash_entry {
 } hash_entry_t;
 
 archive_config_t *init_global_db(char *configfile);
+int setup_db_config_s(archive_config_t *cfg, uint32_t chunksize, uint64_t *user_chunk_sz,
+		 int *pct_interval, const char *algo, cksum_t ck, cksum_t ck_sim,
+		 size_t file_sz, uint32_t *hash_slots, int *hash_entry_size,
+		 uint32_t *intervals, uint64_t *memreqd, size_t memlimit);
 archive_config_t *init_global_db_s(char *path, char *tmppath, uint32_t chunksize,
 			uint64_t user_chunk_sz, int pct_interval, const char *algo,
 			cksum_t ck, cksum_t ck_sim, size_t file_sz, size_t memlimit,

rabin/global/dedupe_config.h

@@ -37,6 +37,7 @@ extern "C" {
 #define	DEFAULT_CHUNK_CKSUM	CKSUM_SHA256
 #define	DEFAULT_SIMILARITY_CKSUM	CKSUM_BLAKE256
 #define	DEFAULT_COMPRESS		COMPRESS_LZ4
+#define	DEFAULT_PCT_INTERVAL	2
 #define	CONTAINER_ITEMS		2048
 #define	MIN_CK 1
 #define	MAX_CK 5
@@ -77,6 +78,7 @@ typedef struct {
 	int seg_fd_w; 
 	int *seg_fd_r; // One read-only fd per thread for mapping in portions of the
 		       // segment metadata cache.
+	int valid;
 	void *dbdata;
 } archive_config_t;
 

rabin/rabin_dedup.c

@@ -126,6 +126,27 @@ dedupe_buf_extra(uint64_t chunksize, int rab_blk_sz, const char *algo, int delta
 	return ((chunksize / dedupe_min_blksz(rab_blk_sz)) * sizeof (uint32_t));
 }
 
+/*
+ * Helper function to let caller size the the user specific compression chunk/segment
+ * to align with deduplication requirements.
+ */
+int
+global_dedupe_chkmem(uint32_t chunksize, uint64_t *user_chunk_sz, int pct_interval,
+		 const char *algo, cksum_t ck, cksum_t ck_sim, size_t file_sz,
+		 size_t memlimit, int nthreads)
+{
+	uint64_t memreqd;
+	archive_config_t cfg;
+	int rv, pct_i, hash_entry_size;
+	uint32_t intervals, hash_slots;
+
+	rv = 0;
+	pct_i = pct_interval;
+	rv = setup_db_config_s(&cfg, chunksize, user_chunk_sz, &pct_i, algo, ck, ck_sim,
+		 file_sz, &hash_slots, &hash_entry_size, &intervals, &memreqd, memlimit);
+	return (rv);
+}
+
 /*
  * Initialize the algorithm with the default params.
  */
@@ -181,12 +202,26 @@ create_dedupe_context(uint64_t chunksize, uint64_t real_chunksize, int rab_blk_s
 		 */
 		if (dedupe_flag == RABIN_DEDUPE_FILE_GLOBAL && op == COMPRESS && rab_blk_sz > 0) {
 			my_sysinfo msys_info;
+			char *val;
 
 			/*
 			 * Get available free memory.
 			 */
 			get_sysinfo(&msys_info);
 
+			if ((val = getenv("PCOMPRESS_INDEX_MEM")) != NULL) {
+				uint64_t mem;
+
+				/*
+				 * Externally specified index limit in MB.
+				 */
+				mem = strtoull(val, NULL, 0);
+				mem *= (1024 * 1024);
+				if (mem > (1024 * 1024) && mem < msys_info.freeram) {
+					msys_info.freeram = mem;
+				}
+			}
+
 			/*
 			 * Use a maximum of approx 75% of free RAM for the index.
 			 */
@@ -773,6 +808,12 @@ process_blocks:
 				}
 				pos1 = tgt - ctx->cbuf;
 				blknum |= GLOBAL_FLAG;
+
+			} else {
+				/*
+				 * Segmented similarity based Dedupe.
+				 */
+				
 			}
 			goto dedupe_done;
 		}

rabin/rabin_dedup.h

@@ -127,7 +127,6 @@
 #define	RABIN_DEDUPE_SEGMENTED	0
 #define	RABIN_DEDUPE_FIXED	1
 #define	RABIN_DEDUPE_FILE_GLOBAL	2
-#define	DEFAULT_PCT_INTERVAL	2
 
 // Mask to extract value from a rabin index entry
 #define	RABIN_INDEX_VALUE (0x3FFFFFFFUL)
@@ -209,5 +208,8 @@ extern void update_dedupe_hdr(uchar_t *buf, uint64_t dedupe_index_sz_cmp,
 extern void reset_dedupe_context(dedupe_context_t *ctx);
 extern uint32_t dedupe_buf_extra(uint64_t chunksize, int rab_blk_sz, const char *algo,
 	int delta_flag);
+extern int global_dedupe_chkmem(uint32_t chunksize, uint64_t *user_chunk_sz, int pct_interval,
+	const char *algo, cksum_t ck, cksum_t ck_sim, size_t file_sz,
+	size_t memlimit, int nthreads);
 
 #endif /* _RABIN_POLY_H_ */