git.m6w6.name Git - awesomized/libmemcached/blob - docs/bin/memaslap.rst

   1 ==================================================
   2 memaslap - Load testing  and benchmarking a server
   3 ==================================================
   4
   5
   6 --------
   7 SYNOPSIS
   8 --------
   9
  10 memaslap [options]
  11
  12 .. program:: memaslap
  13
  14 .. option:: --help
  15
  16 -----------
  17 DESCRIPTION
  18 -----------
  19
  20
  21 memaslap is a load generation and benchmark tool for :program:`memcached()`
  22 servers. It generates configurable workload such as threads, concurrencies, connections, run time, overwrite, miss rate, key size, value size, get/set proportion, expected throughput, and so on. Furthermore, it also testss data
  23 verification, expire-time verification, UDP, binary protocol, facebook test,
  24 replication test, multi-get and reconnection, etc.
  25
  26 Memslap manages network connections like memcached with
  27 libevent. Each thread of memaslap is bound with a CPU core, all
  28 the threads don't communicate with each other, and there are several socket
  29 connections in each thread. Each connection keeps key size distribution,
  30 value size distribution, and command distribution by itself.
  31
  32 You can specify servers via the :option:`--servers` option or via the
  33 environment variable :envvar:`MEMCACHED_SERVERS`.
  34
  35
  36 --------
  37 FEATURES
  38 --------
  39
  40
  41 Memslap is developed to for the following purposes:
  42
  43
  44 Manages network connections with libevent asynchronously.
  45
  46
  47
  48 Set both TCP and UDP up to use non-blocking IO.
  49
  50
  51
  52 Improves parallelism: higher performance in multi-threads environments.
  53
  54
  55
  56 Improves time efficiency: faster processing speed.
  57
  58
  59
  60 Generates key and value more efficiently; key size distribution and value size distribution are configurable.
  61
  62
  63
  64 Supports get, multi-get, and set commands; command distribution is configurable.
  65
  66
  67
  68 Supports controllable miss rate and overwrite rate.
  69
  70
  71
  72 Supports data and expire-time verification.
  73
  74
  75
  76 Supports dumping statistic information periodically.
  77
  78
  79
  80 Supports thousands of TCP connections.
  81
  82
  83
  84 Supports binary protocol.
  85
  86
  87
  88 Supports facebook test (set with TCP and multi-get with UDP) and replication test.
  89
  90
  91
  92
  93 -------
  94 DETAILS
  95 -------
  96
  97
  98 Effective implementation of network.
  99 ____________________________________
 100
 101
 102 For memaslap, both TCP and UDP use non-blocking network IO. All
 103 the network events are managed by libevent as memcached. The network module
 104 of memaslap is similar to memcached. Libevent can ensure
 105 memaslap can handle network very efficiently.
 106
 107
 108 Effective implementation of multi-threads and concurrency
 109 _________________________________________________________
 110
 111
 112 Memslap has the similar implementation of multi-threads to
 113 memcached. Memslap creates one or more self-governed threads;
 114 each thread is bound with one CPU core if the system testss setting CPU
 115 core affinity.
 116
 117 In addition, each thread has a libevent to manage the events of the network;
 118 each thread has one or more self-governed concurrencies; and each
 119 concurrency has one or more socket connections. All the concurrencies don’t
 120 communicate with each other even though they are in the same thread.
 121
 122 Memslap can create thousands of socket connections, and each
 123 concurrency has tens of socket connections. Each concurrency randomly or
 124 sequentially selects one socket connection from its socket connection pool
 125 to run, so memaslap can ensure each concurrency handles one
 126 socket connection at any given time. Users can specify the number of
 127 concurrency and socket connections of each concurrency according to their
 128 expected workload.
 129
 130
 131 Effective implementation of generating key and value
 132 ____________________________________________________
 133
 134
 135 In order to improve time efficiency and space efficiency,
 136 memaslap creates a random characters table with 10M characters. All the
 137 suffixes of keys and values are generated from this random characters table.
 138
 139 Memslap uses the offset in the character table and the length
 140 of the string to identify a string. It can save much memory.
 141 Each key contains two parts, a prefix and a suffix. The prefix is an
 142 uint64_t, 8 bytes. In order to verify the data set before,
 143 memaslap need to ensure each key is unique, so it uses the prefix to identify
 144 a key. The prefix cannot include illegal characters, such as ‘\r’, ‘\n’,
 145 ‘\0’ and ‘ ‘. And memaslap has an algorithm to ensure that.
 146
 147 Memslap doesn’t generate all the objects (key-value pairs) at
 148 the beginning. It only generates enough objects to fill the task window
 149 (default 10K objects) of each concurrency. Each object has the following
 150 basic information, key prefix, key suffix offset in the character table, key
 151 length, value offset in the character table, and value length.
 152
 153 In the work process, each concurrency sequentially or randomly selects an
 154 object from the window to do set operation or get operation. At the same
 155 time, each concurrency kicks objects out of its window and adds new object
 156 into it.
 157
 158
 159 Simple but useful task scheduling
 160 _________________________________
 161
 162
 163 Memslap uses libevent to schedule all the concurrencies of
 164 threads, and each concurrency schedules tasks based on the local task
 165 window. Memslap assumes that if each concurrency keeps the same
 166 key distribution, value distribution and commands distribution, from
 167 outside, memaslap keeps all the distribution as a whole.
 168 Each task window includes a lot of objects, each object stores its basic
 169 information, such as key, value, expire time, and so on. At any time, all
 170 the objects in the window keep the same and fixed key and value
 171 distribution. If an object is overwritten, the value of the object will be
 172 updated. Memslap verifies the data or expire-time according to
 173 the object information stored in the task window.
 174
 175 Libevent selects which concurrency to handle based on a specific network
 176 event. Then the concurrency selects which command (get or set) to operate
 177 based on the command distribution. If it needs to kick out an old object and
 178 add a new object, in order to keep the same key and value distribution, the
 179 new object must have the same key length and value length.
 180
 181 If memcached server has two cache layers (memory and SSD), running
 182 memaslap with different window sizes can get different cache
 183 miss rates. If memaslap adds enough objects into the windows at
 184 the beginning, and the cache of memcached cannot store all the objects
 185 initialized, then memaslap will get some objects from the second
 186 cache layer. It causes the first cache layer to miss. So the user can
 187 specify the window size to get the expected miss rate of the first cache
 188 layer.
 189
 190
 191 Useful implementation of multi-servers , UDP, TCP, multi-get and binary protocol
 192 ________________________________________________________________________________
 193
 194
 195 Because each thread is self-governed, memaslap can assign
 196 different threads to handle different memcached servers. This is just one of
 197 the ways in which memaslap testss multiple servers. The only
 198 limitation is that the number of servers cannot be greater than the number
 199 of threads. The other way to tests multiple servers is for replication
 200 test. Each concurrency has one socket connection to each memcached server.
 201 For the implementation, memaslap can set some objects to one
 202 memcached server, and get these objects from the other servers.
 203
 204 By default, Memslap does single get. If the user specifies
 205 multi-get option, memaslap will collect enough get commands and
 206 pack and send the commands together.
 207
 208 Memslap testss both the ASCII protocol and binary protocol,
 209 but it runs on the ASCII protocol by default.
 210 Memslap by default runs on the TCP protocol, but it also
 211 testss UDP. Because UDP is unreliable, dropped packages and out-of-order
 212 packages may occur. Memslap creates a memory buffer to handle
 213 these problems. Memslap tries to read all the response data of
 214 one command from the server and reorders the response data. If some packages
 215 get lost, the waiting timeout mechanism can ensure half-baked packages will
 216 be discarded and the next command will be sent.
 217
 218
 219
 220 -----
 221 USAGE
 222 -----
 223
 224
 225 Below are some usage samples:
 226
 227
 228 memaslap -s 127.0.0.1:11211 -S 5s
 229
 230
 231
 232 memaslap -s 127.0.0.1:11211 -t 2m -v 0.2 -e 0.05 -b
 233
 234
 235
 236 memaslap -s 127.0.0.1:11211 -F config -t 2m -w 40k -S 20s -o 0.2
 237
 238
 239
 240 memaslap -s 127.0.0.1:11211 -F config -t 2m -T 4 -c 128 -d 20 -P 40k
 241
 242
 243
 244 memaslap -s 127.0.0.1:11211 -F config -t 2m -d 50 -a -n 40
 245
 246
 247
 248 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m
 249
 250
 251
 252 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m -p 2
 253
 254
 255
 256 The user must specify one server at least to run memaslap. The
 257 rest of the parameters have default values, as shown below:
 258
 259 Thread number = 1                    Concurrency = 16
 260
 261 Run time = 600 seconds                Configuration file = NULL
 262
 263 Key size = 64                         Value size = 1024
 264
 265 Get/set = 9:1                         Window size = 10k
 266
 267 Execute number = 0                   Single get = true
 268
 269 Multi-get = false                      Number of sockets of each concurrency = 1
 270
 271 Reconnect = false                     Data verification = false
 272
 273 Expire-time verification = false           ASCII protocol = true
 274
 275 Binary protocol = false                 Dumping statistic information
 276
 277 periodically = false
 278
 279 Overwrite proportion = 0%             UDP = false
 280
 281 TCP = true                           Limit throughput = false
 282
 283 Facebook test = false                  Replication test = false
 284
 285 Key size, value size and command distribution.
 286 ______________________________________________
 287
 288
 289 All the distributions are read from the configuration file specified by user
 290 with “—cfg_cmd” option. If the user does not specify a configuration file,
 291 memaslap will run with the default distribution (key size = 64,
 292 value size = 1024, get/set = 9:1). For information on how to edit the
 293 configuration file, refer to the “Configuration File” section.
 294
 295 The minimum key size is 16 bytes; the maximum key size is 250 bytes. The
 296 precision of proportion is 0.001. The proportion of distribution will be
 297 rounded to 3 decimal places.
 298
 299 The minimum value size is 1 bytes; the maximum value size is 1M bytes. The
 300 precision of proportion is 0.001. The proportion of distribution will be
 301 rounded to 3 decimal places.
 302 Currently, memaslap only testss set and get commands. And it
 303 testss 100% set and 100% get. For 100% get, it will preset some objects to
 304 the server.
 305
 306
 307 Multi-thread and concurrency
 308 ____________________________
 309
 310
 311 The high performance of memaslap benefits from the special
 312 schedule of thread and concurrency. It’s important to specify the proper
 313 number of them. The default number of threads is 1; the default number of
 314 concurrency is 16. The user can use “—threads” and “--concurrency” to
 315 specify these variables.
 316
 317 If the system testss setting CPU affinity and the number of threads
 318 specified by the user is greater than 1, memaslap will try to
 319 bind each thread to a different CPU core. So if you want to get the best
 320 performance memaslap, it is better to specify the number of
 321 thread equal to the number of CPU cores. The number of threads specified by
 322 the user can also be less or greater than the number of CPU cores. Because
 323 of the limitation of implementation, the number of concurrencies could be
 324 the multiple of the number of threads.
 325
 326 1. For 8 CPU cores system
 327
 328 For example:
 329
 330 --threads=2 --concurrency=128
 331
 332 --threads=8 --concurrency=128
 333
 334 --threads=8 --concurrency=256
 335
 336 --threads=12 --concurrency=144
 337
 338 2. For 16 CPU cores system
 339
 340 For example:
 341
 342 --threads=8 --concurrency=128
 343
 344 --threads=16 --concurrency=256
 345
 346 --threads=16 --concurrency=512
 347
 348 --threads=24 --concurrency=288
 349
 350 The memaslap performs very well, when
 351 used to test the performance of memcached servers.
 352 Most of the time, the bottleneck is the network or
 353 the server. If for some reason the user wants to
 354 limit the performance of memaslap, there
 355 are two ways to do this:
 356
 357 Decrease the number of threads and concurrencies.
 358 Use the option “--tps” that memaslap
 359 provides to limit the throughput. This option allows
 360 the user to get the expected throughput. For
 361 example, assume that the maximum throughput is 50
 362 kops/s for a specific configuration, you can specify
 363 the throughput equal to or less than the maximum
 364 throughput using “--tps” option.
 365
 366
 367 Window size
 368 ___________
 369
 370
 371 Most of the time, the user does not need to specify the window size. The
 372 default window size is 10k. For Schooner Memcached, the user can specify
 373 different window sizes to get different cache miss rates based on the test
 374 case. Memslap testss cache miss rate between 0% and 100%.
 375 If you use this utility to test the performance of Schooner Memcached, you
 376 can specify a proper window size to get the expected cache miss rate. The
 377 formula for calculating window size is as follows:
 378
 379 Assume that the key size is 128 bytes, and the value size is 2048 bytes, and
 380 concurrency=128.
 381
 382 1. Small cache cache_size=1M, 100% cache miss (all data get from SSD).
 383 win_size=10k
 384
 385 2. cache_size=4G
 386
 387 (1). cache miss rate 0%
 388
 389 win_size=8k
 390
 391 (2). cache miss rate 5%
 392
 393 win_size=11k
 394
 395 3. cache_size=16G
 396
 397 (1). cache miss rate 0%
 398
 399 win_size=32k
 400
 401 (2). cache miss
 402
 403 rate 5%
 404
 405 win_size=46k
 406
 407 The formula for calculating window size for cache miss rate 0%:
 408
 409 cache_size / concurrency / (key_size + value_size) \* 0.5
 410
 411 The formula for calculating window size for cache miss rate 5%:
 412
 413 cache_size / concurrency / (key_size + value_size) \* 0.7
 414
 415
 416 Verification
 417 ____________
 418
 419
 420 Memslap testss both data verification and expire-time
 421 verification. The user can use "--verify=" or "-v" to specify the proportion
 422 of data verification. In theory, it testss 100% data verification. The
 423 user can use "--exp_verify=" or "-e" to specify the proportion of
 424 expire-time verification. In theory, it testss 100% expire-time
 425 verification. Specify the "--verbose" options to get more detailed error
 426 information.
 427
 428 For example: --exp_verify=0.01 –verify=0.1 , it means that 1% of the objects
 429 set with expire-time, 10% of the objects gotten will be verified. If the
 430 objects are gotten, memaslap will verify the expire-time and
 431 value.
 432
 433
 434 multi-servers and multi-config
 435 _______________________________
 436
 437
 438 Memslap testss multi-servers based on self-governed thread.
 439 There is a limitation that the number of servers cannot be greater than the
 440 number of threads. Memslap assigns one thread to handle one
 441 server at least. The user can use the "--servers=" or "-s" option to specify
 442 multi-servers.
 443
 444 For example:
 445
 446 --servers=10.1.1.1:11211,10.1.1.2:11212,10.1.1.3:11213 --threads=6 --concurrency=36
 447
 448 The above command means that there are 6 threads, with each thread having 6
 449 concurrencies and that threads 0 and 3 handle server 0 (10.1.1.1); threads 1
 450 and 4 handle server 1 (10.1.1.2); and thread 2 and 5 handle server 2
 451 (10.1.1.3).
 452
 453 All the threads and concurrencies in memaslap are self-governed.
 454
 455 So is memaslap. The user can start up several
 456 memaslap instances. The user can run memaslap on different client
 457 machines to communicate with the same memcached server at the same. It is
 458 recommended that the user start different memaslap on different
 459 machines using the same configuration.
 460
 461
 462 Run with execute number mode or time mode
 463 _________________________________________
 464
 465
 466 The default memaslap runs with time mode. The default run time
 467 is 10 minutes. If it times out, memaslap will exit. Do not
 468 specify both execute number mode and time mode at the same time; just
 469 specify one instead.
 470
 471 For example:
 472
 473 --time=30s (It means the test will run 30 seconds.)
 474
 475 --execute_number=100000 (It means that after running 100000 commands, the test will exit.)
 476
 477
 478 Dump statistic information periodically.
 479 ________________________________________
 480
 481
 482 The user can use "--stat_freq=" or "-S" to specify the frequency.
 483
 484 For example:
 485
 486 --stat_freq=20s
 487
 488 Memslap will dump the statistics of the commands (get and set) at the frequency of every 20
 489 seconds.
 490
 491 For more information on the format of dumping statistic information, refer to “Format of Output” section.
 492
 493
 494 Multi-get
 495 _________
 496
 497
 498 The user can use "--division=" or "-d" to specify multi-get keys count.
 499 Memslap by default does single get with TCP. Memslap also testss data
 500 verification and expire-time verification for multi-get.
 501
 502 Memslap testss multi-get with both TCP and UDP. Because of
 503 the different implementation of the ASCII protocol and binary protocol,
 504 there are some differences between the two. For the ASCII protocol,
 505 memaslap sends one “multi-get” to the server once. For the
 506 binary protocol, memaslap sends several single get commands
 507 together as “multi-get” to the server.
 508
 509
 510 UDP and TCP
 511 ___________
 512
 513
 514 Memslap testss both UDP and TCP. For TCP,
 515 memaslap does not reconnect the memcached server if socket connections are
 516 lost. If all the socket connections are lost or memcached server crashes,
 517 memaslap will exit. If the user specifies the “--reconnect”
 518 option when socket connections are lost, it will reconnect them.
 519
 520 User can use “--udp” to enable the UDP feature, but UDP comes with some
 521 limitations:
 522
 523 UDP cannot set data more than 1400 bytes.
 524
 525 UDP is not testsed by the binary protocol because the binary protocol of
 526 memcached does not tests that.
 527
 528 UDP doesn’t tests reconnection.
 529
 530
 531 Facebook test
 532 _____________
 533
 534
 535 Set data with TCP and multi-get with UDP. Specify the following options:
 536
 537 "--facebook --division=50"
 538
 539 If you want to create thousands of TCP connections, specify the
 540
 541 "--conn_sock=" option.
 542
 543 For example: --facebook --division=50 --conn_sock=200
 544
 545 The above command means that memaslap will do facebook test,
 546 each concurrency has 200 socket TCP connections and one UDP socket.
 547
 548 Memslap sets objects with the TCP socket, and multi-gets 50
 549 objects once with the UDP socket.
 550
 551 If you specify "--division=50", the key size must be less that 25 bytes
 552 because the UDP packet size is 1400 bytes.
 553
 554
 555 Replication test
 556 ________________
 557
 558
 559 For replication test, the user must specify at least two memcached servers.
 560 The user can use “—rep_write=” option to enable feature.
 561
 562 For example:
 563
 564 --servers=10.1.1.1:11211,10.1.1.2:11212 –rep_write=2
 565
 566 The above command means that there are 2 replication memcached servers,
 567 memaslap will set objects to both server 0 and server 1, get
 568 objects which are set to server 0 before from server 1, and also get objects
 569 which are set to server 1 before from server 0. If server 0 crashes,
 570 memaslap will only get objects from server 1. If server 0 comes
 571 back to life again, memaslap will reconnect server 0. If both
 572 server 0 and server 1 crash, memaslap will exit.
 573
 574
 575 Supports thousands of TCP connections
 576 _____________________________________
 577
 578
 579 Start memaslap with "--conn_sock=" or "-n" to enable this
 580 feature. Make sure that your system can tests opening thousands of files
 581 and creating thousands of sockets. However, this feature does not tests
 582 reconnection if sockets disconnect.
 583
 584 For example:
 585
 586 --threads=8 --concurrency=128 --conn_sock=128
 587
 588 The above command means that memaslap starts up 8 threads, each
 589 thread has 16 concurrencies, each concurrency has 128 TCP socket
 590 connections, and the total number of TCP socket connections is 128 \* 128 =
 591 16384.
 592
 593
 594 Supports binary protocol
 595 ________________________
 596
 597
 598 Start memaslap with "--binary" or "-B" options to enable this
 599 feature. It testss all the above features except UDP, because the latest
 600 memcached 1.3.3 does not implement binary UDP protocol.
 601
 602 For example:
 603
 604 --binary
 605
 606 Since memcached 1.3.3 doesn't implement binary UDP protocol,
 607 memaslap does not tests UDP. In addition, memcached 1.3.3 does not tests
 608 multi-get. If you specify "--division=50" option, it just sends 50 get
 609 commands together as “mulit-get” to the server.
 610
 611
 612
 613 ------------------
 614 Configuration file
 615 ------------------
 616
 617
 618 This section describes the format of the configuration file.  By default
 619 when no configuration file is specified memaslap reads the default
 620 one located at ~/.memaslap.cnf.
 621
 622 Below is a sample configuration file:
 623
 624
 625 .. code-block:: perl
 626
 627   ---------------------------------------------------------------------------
 628   #comments should start with '#'
 629   #key
 630   #start_len end_len proportion
 631   #
 632   #key length range from start_len to end_len
 633   #start_len must be equal to or greater than 16
 634   #end_len must be equal to or less than 250
 635   #start_len must be equal to or greater than end_len
 636   #memaslap will generate keys according to the key range
 637   #proportion: indicates keys generated from one range accounts for the total
 638   generated keys
 639   #
 640   #example1: key range 16~100 accounts for 80%
 641   #          key range 101~200 accounts for 10%
 642   #          key range 201~250 accounts for 10%
 643   #          total should be 1 (0.8+0.1+0.1 = 1)
 644   #
 645   #          16 100 0.8
 646   #          101 200 0.1
 647   #          201 249 0.1
 648   #
 649   #example2: all keys length are 128 bytes
 650   #
 651   #          128 128 1
 652   key
 653   128 128 1
 654   #value
 655   #start_len end_len proportion
 656   #
 657   #value length range from start_len to end_len
 658   #start_len must be equal to or greater than 1
 659   #end_len must be equal to or less than 1M
 660   #start_len must be equal to or greater than end_len
 661   #memaslap will generate values according to the value range
 662   #proportion: indicates values generated from one range accounts for the
 663   total generated values
 664   #
 665   #example1: value range 1~1000 accounts for 80%
 666   #          value range 1001~10000 accounts for 10%
 667   #          value range 10001~100000 accounts for 10%
 668   #          total should be 1 (0.8+0.1+0.1 = 1)
 669   #
 670   #          1 1000 0.8
 671   #          1001 10000 0.1
 672   #          10001 100000 0.1
 673   #
 674   #example2: all value length are 128 bytes
 675   #
 676   #          128 128 1
 677   value
 678   2048 2048 1
 679   #cmd
 680   #cmd_type cmd_proportion
 681   #
 682   #currently memaslap only testss get and set command.
 683   #
 684   #cmd_type
 685   #set     0
 686   #get     1
 687   #
 688   #example: set command accounts for 50%
 689   #         get command accounts for 50%
 690   #         total should be 1 (0.5+0.5 = 1)
 691   #
 692   #         cmd
 693   #         0    0.5
 694   #         1    0.5
 695   cmd
 696   0    0.1
 697   1.0 0.9
 698
 699
 700
 701 ----------------
 702 Format of output
 703 ----------------
 704
 705
 706 At the beginning, memaslap displays some configuration information as follows:
 707
 708
 709 servers : 127.0.0.1:11211
 710
 711
 712
 713 threads count: 1
 714
 715
 716
 717 concurrency: 16
 718
 719
 720
 721 run time: 20s
 722
 723
 724
 725 windows size: 10k
 726
 727
 728
 729 set proportion: set_prop=0.10
 730
 731
 732
 733 get proportion: get_prop=0.90
 734
 735
 736
 737 Where
 738 _____
 739
 740
 741
 742 servers : "servers"
 743
 744  The servers used by memaslap.
 745
 746
 747
 748 threads count
 749
 750  The number of threads memaslap runs with.
 751
 752
 753
 754 concurrency
 755
 756  The number of concurrencies memaslap runs with.
 757
 758
 759
 760 run time
 761
 762  How long to run memaslap.
 763
 764
 765
 766 windows size
 767
 768  The task window size of each concurrency.
 769
 770
 771
 772 set proportion
 773
 774  The proportion of set command.
 775
 776
 777
 778 get proportion
 779
 780  The proportion of get command.
 781
 782
 783
 784 The output of dynamic statistics is something like this:
 785
 786
 787 .. code-block:: perl
 788
 789   ---------------------------------------------------------------------------------------------------------------------------------
 790   Get Statistics
 791   Type  Time(s)  Ops   TPS(ops/s)  Net(M/s)  Get_miss  Min(us)  Max(us)
 792   Avg(us)  Std_dev    Geo_dist
 793   Period   5   345826  69165     65.3      0         27      2198     203
 794   95.43      177.29
 795   Global  20  1257935  62896     71.8      0         26      3791     224
 796   117.79     192.60
 797
 798
 799   Set Statistics
 800   Type  Time(s)  Ops   TPS(ops/s)  Net(M/s)  Get_miss  Min(us)  Max(us)
 801   Avg(us)  Std_dev    Geo_dist
 802   Period   5    38425   7685      7.3       0         42      628     240
 803   88.05      220.21
 804   Global   20   139780  6989      8.0       0         37      3790    253
 805   117.93     224.83
 806
 807
 808   Total Statistics
 809   Type  Time(s)  Ops   TPS(ops/s)  Net(M/s)  Get_miss  Min(us)  Max(us)
 810   Avg(us)  Std_dev    Geo_dist
 811   Period   5   384252   76850     72.5      0        27      2198     207
 812   94.72      181.18
 813   Global  20  1397720   69886     79.7      0        26      3791     227
 814   117.93     195.60
 815   ---------------------------------------------------------------------------------------------------------------------------------
 816
 817
 818
 819 Where
 820 _____
 821
 822
 823
 824 Get Statistics
 825
 826  Statistics information of get command
 827
 828
 829
 830 Set Statistics
 831
 832  Statistics information of set command
 833
 834
 835
 836 Total Statistics
 837
 838  Statistics information of both get and set command
 839
 840
 841
 842 Period
 843
 844  Result within a period
 845
 846
 847
 848 Global
 849
 850  Accumulated results
 851
 852
 853
 854 Ops
 855
 856  Total operations
 857
 858
 859
 860 TPS
 861
 862  Throughput, operations/second
 863
 864
 865
 866 Net
 867
 868  The rate of network
 869
 870
 871
 872 Get_miss
 873
 874  How many objects can’t be gotten
 875
 876
 877
 878 Min
 879
 880  The minimum response time
 881
 882
 883
 884 Max
 885
 886  The maximum response time
 887
 888
 889
 890 Avg:
 891
 892  The average response time
 893
 894
 895
 896 Std_dev
 897
 898  Standard deviation of response time
 899
 900
 901
 902 Geo_dist
 903
 904  Geometric distribution based on natural exponential function
 905
 906
 907
 908 At the end, memaslap will output something like this:
 909
 910
 911 .. code-block:: perl
 912
 913    ---------------------------------------------------------------------------------------------------------------------------------
 914    Get Statistics (1257956 events)
 915      Min:        26
 916      Max:      3791
 917      Avg:       224
 918      Geo:    192.60
 919      Std:    116.23
 920                      Log2 Dist:
 921                        4:        0       10    84490   215345
 922                        8:   484890   459823    12543      824
 923                       12:       31
 924
 925     Set Statistics (139782 events)
 926        Min:        37
 927        Max:      3790
 928        Avg:       253
 929        Geo:    224.84
 930        Std:    116.83
 931        Log2 Dist:
 932          4:        0        0     4200 16988
 933          8:    50784    65574 2064      167
 934          12:        5
 935
 936      Total Statistics (1397738 events)
 937          Min:        26
 938          Max:      3791
 939          Avg:       227
 940          Geo:    195.60
 941          Std:    116.60
 942          Log2 Dist:
 943            4:        0       10    88690   232333
 944            8:   535674   525397    14607      991
 945            12:       36
 946
 947    cmd_get: 1257969
 948    cmd_set: 139785
 949    get_misses: 0
 950    verify_misses: 0
 951    verify_failed: 0
 952    expired_get: 0
 953    unexpired_unget: 0
 954    written_bytes: 242516030
 955    read_bytes: 1003702556
 956    object_bytes: 152086080
 957    packet_disorder: 0
 958    packet_drop: 0
 959    udp_timeout: 0
 960
 961    Run time: 20.0s Ops: 1397754 TPS: 69817 Net_rate: 59.4M/s
 962    ---------------------------------------------------------------------------------------------------------------------------------
 963
 964
 965
 966 Where
 967 _____
 968
 969
 970
 971 Get Statistics
 972
 973  Get statistics of response time
 974
 975
 976
 977 Set Statistics
 978
 979  Set statistics of response time
 980
 981
 982
 983 Total Statistics
 984
 985  Both get and set statistics of response time
 986
 987
 988
 989 Min
 990
 991  The accumulated and minimum response time
 992
 993
 994
 995 Max
 996
 997  The accumulated and maximum response time
 998
 999
1000
1001 Avg
1002
1003  The accumulated and average response time
1004
1005
1006
1007 Std
1008
1009  Standard deviation of response time
1010
1011
1012
1013 Log2 Dist
1014
1015  Geometric distribution based on logarithm 2
1016
1017
1018
1019 cmd_get
1020
1021  Total get commands done
1022
1023
1024
1025 cmd_set
1026
1027  Total set commands done
1028
1029
1030
1031 get_misses
1032
1033  How many objects can’t be gotten from server
1034
1035
1036
1037 verify_misses
1038
1039  How many objects need to verify but can’t get them
1040
1041
1042
1043 verify_failed
1044
1045  How many objects with insistent value
1046
1047
1048
1049 expired_get
1050
1051  How many objects are expired but we get them
1052
1053
1054
1055 unexpired_unget
1056
1057  How many objects are unexpired but we can’t get them
1058
1059
1060
1061 written_bytes
1062
1063  Total written bytes
1064
1065
1066
1067 read_bytes
1068
1069  Total read bytes
1070
1071
1072
1073 object_bytes
1074
1075  Total object bytes
1076
1077
1078
1079 packet_disorder
1080
1081  How many UDP packages are disorder
1082
1083
1084
1085 packet_drop
1086
1087  How many UDP packages are lost
1088
1089
1090
1091 udp_timeout
1092
1093  How many times UDP time out happen
1094
1095
1096
1097 Run time
1098
1099  Total run time
1100
1101
1102
1103 Ops
1104
1105  Total operations
1106
1107
1108
1109 TPS
1110
1111  Throughput, operations/second
1112
1113
1114
1115 Net_rate
1116
1117  The average rate of network
1118
1119
1120
1121
1122
1123 -------
1124 OPTIONS
1125 -------
1126
1127
1128 -s, --servers=
1129     List one or more servers to connect. Servers count must be less than
1130     threads count. e.g.: --servers=localhost:1234,localhost:11211
1131
1132 -T, --threads=
1133     Number of threads to startup, better equal to CPU numbers. Default 8.
1134
1135 -c, --concurrency=
1136     Number of concurrency to simulate with load. Default 128.
1137
1138 -n, --conn_sock=
1139     Number of TCP socks per concurrency. Default 1.
1140
1141 -x, --execute_number=
1142     Number of operations(get and set) to execute for the
1143     given test. Default 1000000.
1144
1145 -t, --time=
1146     How long the test to run, suffix: s-seconds, m-minutes, h-hours,
1147     d-days e.g.: --time=2h.
1148
1149 -F, --cfg_cmd=
1150     Load the configure file to get command,key and value distribution list.
1151
1152 -w, --win_size=
1153     Task window size of each concurrency, suffix: K, M e.g.: --win_size=10k.
1154     Default 10k.
1155
1156 -X, --fixed_size=
1157     Fixed length of value.
1158
1159 -v, --verify=
1160     The proportion of date verification, e.g.: --verify=0.01
1161
1162 -d, --division=
1163     Number of keys to multi-get once. Default 1, means single get.
1164
1165 -S, --stat_freq=
1166     Frequency of dumping statistic information. suffix: s-seconds,
1167     m-minutes, e.g.: --resp_freq=10s.
1168
1169 -e, --exp_verify=
1170     The proportion of objects with expire time, e.g.: --exp_verify=0.01.
1171     Default no object with expire time
1172
1173 -o, --overwrite=
1174     The proportion of objects need overwrite, e.g.: --overwrite=0.01.
1175     Default never overwrite object.
1176
1177 -R, --reconnect
1178     Reconnect tests, when connection is closed it will be reconnected.
1179
1180 -U, --udp
1181     UDP tests, default memaslap uses TCP, TCP port and UDP port of
1182     server must be same.
1183
1184 -a, --facebook
1185     Whether it enables facebook test feature, set with TCP and multi-get with UDP.
1186
1187 -B, --binary
1188     Whether it enables binary protocol. Default with ASCII protocol.
1189
1190 -P, --tps=
1191     Expected throughput, suffix: K, e.g.: --tps=10k.
1192
1193 -p, --rep_write=
1194     The first nth servers can write data, e.g.: --rep_write=2.
1195
1196 -b, --verbose
1197     Whether it outputs detailed information when verification fails.
1198
1199 -h, --help
1200     Display this message and then exit.
1201
1202 -V, --version
1203     Display the version of the application and then exit.
1204
1205
1206 --------
1207 EXAMPLES
1208 --------
1209
1210
1211 memaslap -s 127.0.0.1:11211 -S 5s
1212
1213 memaslap -s 127.0.0.1:11211 -t 2m -v 0.2 -e 0.05 -b
1214
1215 memaslap -s 127.0.0.1:11211 -F config -t 2m -w 40k -S 20s -o 0.2
1216
1217 memaslap -s 127.0.0.1:11211 -F config -t 2m -T 4 -c 128 -d 20 -P 40k
1218
1219 memaslap -s 127.0.0.1:11211 -F config -t 2m -d 50 -a -n 40
1220
1221 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m
1222
1223 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m -p 2
1224
1225
1226 ----
1227 HOME
1228 ----
1229
1230
1231 To find out more information please check:
1232 `http://libmemcached.org/ <http://libmemcached.org/>`_
1233
1234
1235 -------
1236 AUTHORS
1237 -------
1238
1239
1240 Mingqiang Zhuang <mingqiangzhuang@hengtiansoft.com> (Schooner Technolgy)
1241 Brian Aker, <brian@tangent.org>
1242
1243
1244 --------
1245 SEE ALSO
1246 --------
1247
1248 :manpage:`memcached(1)` :manpage:`libmemcached(3)`