一、前言
Tair支撐了淘寶幾乎所有系統的緩存信息（Tair = Taobao Pair，Pair即Key-Value鍵值對），內置了三個存儲引擎：mdb（默認，類似於Memcache）、rdb（類似於Redis）、ldb（高性能KV存儲），其中前2者定位於cache緩存，ldb則定位於持久化存儲。Tair屬於分布式系統，由一個中心控制節點（Config Server）和一系列的服務節點（Data Server）組成，Config Server負責管理維護所有的Data Server狀態信息。Data Server對外提供各種數據服務，並以心跳（Heartbeat）的形式將自身狀況匯報給Config Server。Config Server是一個輕量級的控制點，可以采用Master-Slaver的形式來保證其可靠性，所有的Data Server地位都是等價的。持久化的數據存放於磁盤中，為了解決磁盤損壞導致的數據丟失, Tair可以配置數據的備份數目, 自動將一份數據的不同備份放到不同的主機上。
本文記錄了詳細的部署操作步驟（基於trunk版本），引用一張官方結構圖，更多關於Tair的介紹請參照官方wiki（http://code.taobao.org/p/tair/wiki/intro/）。
二、安裝Tair Server
1、系統環境：CentOS 6.5 （64位）
2、Tair Server 源碼采用 C++ 編寫，以下基於源碼在linux環境下 make install
3、安裝依賴包（感謝萬能的yum）
1）wiki中描述需要安裝依賴automake 、autoconfig、libtool庫，實際CentOS6.5已經集成了以上lib，如果沒有請通過yum獲取
命令： “ yum install libtool ”
2）安裝boost-devel庫
命令： “ yum install boost-devel ”
3）安裝gcc-c++
命令： “ yum install gcc-c++ ”
4、通過svn獲取 tb-common-utils 和 Tair 源碼
tb-common-utils 的 SVN地址： http://code.taobao.org/svn/tb-common-utils/trunk
Tair 的 SVN地址： http://code.taobao.org/svn/tair/trunk
5、將獲取到的源碼復制到當前用戶目錄，同時手工創建一個名稱為“tairlib”文件夾，作為相關lib文件的安裝路徑，結構如下
6、安裝tb-common-utils庫，從命名可以看出應該是taobao內部開發的公共庫
1）通過終端進入tb-common-utils文件夾，切換到root賬號
2）給build.sh 腳本文件增加可執行X權限，否則可能會提示“權限不夠”
命令： “ chmod +x build.sh ”
3）創建環境變量TBLIB_ROOT指示相關lib文件的安裝路徑，指向之前創建的tairlib文件夾
注意這個是會話級的變量，如果中間關閉終端需要重新export
命令： export TBLIB_ROOT="/home/glf/tairlib"
4）執行build.sh腳本。
5）至此tb-common-utils庫安裝完畢。
7、安裝tair
1）切換進入tair文件夾，如果是重新打開的終端窗口，請切換到root賬號，同時參照6.3使用同樣的命令創建環境變量，tair的安裝同樣需要這個環境變量
2）給bootstrap.sh 腳本文件增加可執行X權限，否則可能提示“權限不夠"
命令： “ chmod +x bootstrap.sh ”
3）執行 bootstrap.sh 腳本
4）執行 configure
5）執行 make
6）執行 make install ，安裝成功后會把tair安裝到 /root/tair_bin ，至此安裝tair 服務器完畢。
因為使用的root賬號安裝，所以安裝目錄為/root，但如果使用當前用戶在安裝過程會提示權限問題，麻煩知道怎么解決的請告之。
三、Tair Server的配置
1、由於機器網絡環境復雜，本文僅以一台機器不同端口號模擬分布式集群部署，如果多機器部署端口可以一致，只需要修改IP即可。
| 名稱 | IP | 端口 |
| Config Server（Master） | 10.0.2.15 | 5198 |
| Config Server（Slaver） | 10.0.2.15 | 5200 |
| Data Server A | 10.0.2.15 | 5191 |
| Data Server B | 10.0.2.15 | 5192 |
關於IP、端口如何配置請參照下面的conf文件，但需要注意的是Config Server的心跳端口（Heartbeat Port）為Port+1，
例如Port=5198那么Heartbeat Port默認=5199，所以在配置其他端口的時候注意預留，不要重復。
2、CP 4份tair_bin文件夾，依次重命名如下圖，后面都在4個CP的目錄修改配置，原tair_bin保留不作任何修改（ 好不容易才裝起來的呀：） ）。
tair_bin_cs1：作為Config Server（Master）目錄
tair_bin_cs2：作為Config Server（Slaver）目錄
tair_bin_ds1：作為Data Server A 目錄
tair_bin_ds2：作為Data Server B 目錄
3、依次在CP的4個目錄下創建（mkdir） data 和 logs 文件夾，用於設置相關配置文件中的路徑（不確定是否必須，也有可能服務啟動的時候會根據conf設置的路徑自動創建）
4、每個Server的etc 目錄下都包含以下文件（安裝時創建的sample文件），相關文件中已經存在對應的配置項解釋說明，
同時可以參照wiki的解釋：http://code.taobao.org/p/tair/wiki/deploy
“configserver.conf.default” （Config Server使用）
“dataserver.conf.default” （Data Server使用）
“group.conf.default” （Config Server使用）
“invalserver.conf.default” （暫未使用）
5、配置Config Server
1）在 tair_bin_cs1 和 tair_bin_cs2 的etc目錄下將 “configserver.conf.default” 重命名為“configserver.conf”，將“group.conf.default”重命名為“group.conf”，作為服務器的正式配置文件。
2）打開 tair_bin_cs1\etc\configserver.conf 參照如下代碼進行配置，其中第一行config_server為master服務器，第二行為slaver服務器，
使用絕對路徑修改 log_file、pid_file、goup_file、data_dir 目錄，使用 ifconfig 命名查看當前網卡的dev_name和ip，以下修改過的內容用紅色字體標識。
（插曲：因為dev_name默認為eth0，我機器實際為eth1，一度陷入了絕境）
# # tair 2.3 --- configserver config # [public] config_server=10.0.2.15:5198 config_server=10.0.2.15:5200 [configserver] port=5198 log_file=/root/tair_bin_cs1/logs/config.log pid_file=/root/tair_bin_cs1/logs/config.pid log_level=warn group_file=/root/tair_bin_cs1/etc/group.conf data_dir=/root/tair_bin_cs1/data/data dev_name=eth1
3）在 tair_bin_cs1\etc\group.conf 參照如下代碼進行配置，主要用於注冊DataSever服務器的IP和Port
#group name
[group_1] # data move is 1 means when some data serve down, the migrating will be start. # default value is 0
_data_move=0
#_min_data_server_count: when data servers left in a group less than this value, config server will stop serve for this group #default value is copy count.
_min_data_server_count=1
#_plugIns_list=libStaticPlugIn.so
_build_strategy=1 #1 normal 2 rack
_build_diff_ratio=0.6 #how much difference is allowd between different rack # diff_ratio = |data_sever_count_in_rack1 - data_server_count_in_rack2| / max (data_sever_count_in_rack1, data_server_count_in_rack2) # diff_ration must less than _build_diff_ratio
_pos_mask=65535 # 65535 is 0xffff this will be used to gernerate rack info. 64 bit serverId & _pos_mask is the rack info,
_copy_count=1 _bucket_number=1023
# accept ds strategy. 1 means accept ds automatically
_accept_strategy=1
# data center A
_server_list=10.0.2.15:5191 _server_list=10.0.2.15:5192
#quota info
_areaCapacity_list=0,1124000;
4）Config Server（Slave）的配置也基本一致，注意修改conf文件中的路徑、ip
configserver.conf 參照如下：
# # tair 2.3 --- configserver config # [public] config_server=10.0.2.15:5198 config_server=10.0.2.15:5200 [configserver] port=5200 log_file=/root/tair_bin_cs2/logs/config.log pid_file=/root/tair_bin_cs2/logs/config.pid log_level=warn group_file=/root/tair_bin_cs2/etc/group.conf data_dir=/root/tair_bin_cs2/data/data dev_name=eth1
group.conf 參照如下：
#group name [group_1] # data move is 1 means when some data serve down, the migrating will be start. # default value is 0 _data_move=0 #_min_data_server_count: when data servers left in a group less than this value, config server will stop serve for this group #default value is copy count. _min_data_server_count=1 #_plugIns_list=libStaticPlugIn.so _build_strategy=1 #1 normal 2 rack _build_diff_ratio=0.6 #how much difference is allowd between different rack # diff_ratio = |data_sever_count_in_rack1 - data_server_count_in_rack2| / max (data_sever_count_in_rack1, data_server_count_in_rack2) # diff_ration must less than _build_diff_ratio _pos_mask=65535 # 65535 is 0xffff this will be used to gernerate rack info. 64 bit serverId & _pos_mask is the rack info, _copy_count=1 _bucket_number=1023 # accept ds strategy. 1 means accept ds automatically _accept_strategy=1 # data center A _server_list=10.0.2.15:5191 _server_list=10.0.2.15:5192 #quota info _areaCapacity_list=0,1124000;
5）至此2台 Config Server 配置完畢
6、配置Data Server（默認為 mdb 引擎）
1）在2個Data Server的 etc 目錄下將 “dataserver.conf.default” 重命名為“dataserver.conf”，作為服務器的正式配置文件
2）打開 tair_bin_ds1\etc\dataserver.conf 參照如下代碼進行修改配置，注意[public]節點的2行config_server必須和configserver上的配置保持一致
# # tair 2.3 --- tairserver config # [public] config_server=10.0.2.15:5198 config_server=10.0.2.15:5200 [tairserver] # #storage_engine: # # mdb # kdb # ldb # storage_engine=mdb local_mode=0 # #mdb_type: # mdb # mdb_shm # mdb_type=mdb_shm # # if you just run 1 tairserver on a computer, you may ignore this option. # if you want to run more than 1 tairserver on a computer, each tairserver must have their own "mdb_shm_path" # # mdb_shm_path=/mdb_shm_path01 #tairserver listen port port=5191 heartbeat_port=6191 process_thread_num=16 # #mdb size in MB # slab_mem_size=1024 log_file=/root/tair_bin_ds1/logs/server.log pid_file=/root/tair_bin_ds1/logs/server.pid log_level=warn dev_name=eth1 ulog_dir=/root/tair_bin_ds1/data/ulog ulog_file_number=3 ulog_file_size=64 check_expired_hour_range=2-4 check_slab_hour_range=5-7 dup_sync=1 do_rsync=0 # much resemble json format # one local cluster config and one or multi remote cluster config. # {local:[master_cs_addr,slave_cs_addr,group_name,timeout_ms,queue_limit],remote:[...],remote:[...]} rsync_conf={local:[10.0.0.1:5198,10.0.0.2:5198,group_local,2000,1000],remote:[10.0.1.1:5198,10.0.1.2:5198,group_remote,2000,3000]} # if same data can be updated in local and remote cluster, then we need care modify time to # reserve latest update when do rsync to each other. rsync_mtime_care=0 # rsync data directory(retry_log/fail_log..) rsync_data_dir=/root/tair_bin_ds1/data/remote # max log file size to record failed rsync data, rotate to a new file when over the limit rsync_fail_log_size=30000000 # whether do retry when rsync failed at first time rsync_do_retry=0 # when doing retry, size limit of retry log's memory use rsync_retry_log_mem_size=100000000 [fdb] # in MB index_mmap_size=30 cache_size=256 bucket_size=10223 free_block_pool_size=8 data_dir=/root/tair_bin_ds1/data/fdb fdb_name=tair_fdb [kdb] # in byte map_size=10485760 # the size of the internal memory-mapped region bucket_size=1048583 # the number of buckets of the hash table record_align=128 # the power of the alignment of record size data_dir=/root/tair_bin_ds1/data/kdb # the directory of kdb's data [ldb] #### ldb manager config ## data dir prefix, db path will be data/ldbxx, "xx" means db instance index. ## so if ldb_db_instance_count = 2, then leveldb will init in ## /data/ldb1/ldb/, /data/ldb2/ldb/. We can mount each disk to ## data/ldb1, data/ldb2, so we can init each instance on each disk. data_dir=/root/tair_bin_ds1/data/ldb ## leveldb instance count, buckets will be well-distributed to instances ldb_db_instance_count=1 ## whether load backup version when startup. ## backup version may be created to maintain some db data of specifid version. ldb_load_backup_version=0 ## whether support version strategy. ## if yes, put will do get operation to update existed items's meta info(version .etc), ## get unexist item is expensive for leveldb. set 0 to disable if nobody even care version stuff. ldb_db_version_care=1 ## time range to compact for gc, 1-1 means do no compaction at all ldb_compact_gc_range = 3-6 ## backgroud task check compact interval (s) ldb_check_compact_interval = 120 ## use cache count, 0 means NOT use cache,`ldb_use_cache_count should NOT be larger ## than `ldb_db_instance_count, and better to be a factor of `ldb_db_instance_count. ## each cache mdb's config depends on mdb's config item(mdb_type, slab_mem_size, etc) ldb_use_cache_count=1 ## cache stat can't report configserver, record stat locally, stat file size. ## file will be rotate when file size is over this. ldb_cache_stat_file_size=20971520 ## migrate item batch size one time (1M) ldb_migrate_batch_size = 3145728 ## migrate item batch count. ## real batch migrate items depends on the smaller size/count ldb_migrate_batch_count = 5000 ## comparator_type bitcmp by default # ldb_comparator_type=numeric ## numeric comparator: special compare method for user_key sorting in order to reducing compact ## parameters for numeric compare. format: [meta][prefix][delimiter][number][suffix] ## skip meta size in compare # ldb_userkey_skip_meta_size=2 ## delimiter between prefix and number # ldb_userkey_num_delimiter=: #### ## use blommfilter ldb_use_bloomfilter=1 ## use mmap to speed up random acess file(sstable),may cost much memory ldb_use_mmap_random_access=0 ## how many highest levels to limit compaction ldb_limit_compact_level_count=0 ## limit compaction ratio: allow doing one compaction every ldb_limit_compact_interval ## 0 means limit all compaction ldb_limit_compact_count_interval=0 ## limit compaction time interval ## 0 means limit all compaction ldb_limit_compact_time_interval=0 ## limit compaction time range, start == end means doing limit the whole day. ldb_limit_compact_time_range=6-1 ## limit delete obsolete files when finishing one compaction ldb_limit_delete_obsolete_file_interval=5 ## whether trigger compaction by seek ldb_do_seek_compaction=0 ## whether split mmt when compaction with user-define logic(bucket range, eg) ldb_do_split_mmt_compaction=0 #### following config effects on FastDump #### ## when ldb_db_instance_count > 1, bucket will be sharded to instance base on config strategy. ## current supported: ## hash : just do integer hash to bucket number then module to instance, instance's balance may be ## not perfect in small buckets set. same bucket will be sharded to same instance ## all the time, so data will be reused even if buckets owned by server changed(maybe cluster has changed), ## map : handle to get better balance among all instances. same bucket may be sharded to different instance based ## on different buckets set(data will be migrated among instances). ldb_bucket_index_to_instance_strategy=map ## bucket index can be updated. this is useful if the cluster wouldn't change once started ## even server down/up accidently. ldb_bucket_index_can_update=1 ## strategy map will save bucket index statistics into file, this is the file's directory ldb_bucket_index_file_dir=/root/tair_bin_ds1/data/bindex ## memory usage for memtable sharded by bucket when batch-put(especially for FastDump) ldb_max_mem_usage_for_memtable=3221225472 #### #### leveldb config (Warning: you should know what you're doing.) ## one leveldb instance max open files(actually table_cache_ capacity, consider as working set, see `ldb_table_cache_size) ldb_max_open_files=65535 ## whether return fail when occure fail when init/load db, and ## if true, read data when compactiong will verify checksum ldb_paranoid_check=0 ## memtable size ldb_write_buffer_size=67108864 ## sstable size ldb_target_file_size=8388608 ## max file size in each level. level-n (n > 0): (n - 1) * 10 * ldb_base_level_size ldb_base_level_size=134217728 ## sstable's block size # ldb_block_size=4096 ## sstable cache size (override `ldb_max_open_files) ldb_table_cache_size=1073741824 ##block cache size ldb_block_cache_size=16777216 ## arena used by memtable, arena block size #ldb_arenablock_size=4096 ## key is prefix-compressed period in block, ## this is period length(how many keys will be prefix-compressed period) # ldb_block_restart_interval=16 ## specifid compression method (snappy only now) # ldb_compression=1 ## compact when sstables count in level-0 is over this trigger ldb_l0_compaction_trigger=1 ## write will slow down when sstables count in level-0 is over this trigger ## or sstables' filesize in level-0 is over trigger * ldb_write_buffer_size if ldb_l0_limit_write_with_count=0 ldb_l0_slowdown_write_trigger=32 ## write will stop(wait until trigger down) ldb_l0_stop_write_trigger=64 ## when write memtable, max level to below maybe ldb_max_memcompact_level=3 ## read verify checksum ldb_read_verify_checksums=0 ## write sync log. (one write will sync log once, expensive) ldb_write_sync=0 ## bits per key when use bloom filter #ldb_bloomfilter_bits_per_key=10 ## filter data base logarithm. filterbasesize=1<<ldb_filter_base_logarithm #ldb_filter_base_logarithm=12
3）另一台DataServer的配置基本一致，參照如下代碼
注意：由於屬於單機部署多個DataServer，需要修改mdb_shm_path=/mdb_shm_path02，（ps：這點我開始沒留意導致每次啟動一個dataserver的時候另一台自動shutdown）
# # tair 2.3 --- tairserver config # [public] config_server=10.0.2.15:5198 config_server=10.0.2.15:5200 [tairserver] # #storage_engine: # # mdb # kdb # ldb # storage_engine=mdb local_mode=0 # #mdb_type: # mdb # mdb_shm # mdb_type=mdb_shm # # if you just run 1 tairserver on a computer, you may ignore this option. # if you want to run more than 1 tairserver on a computer, each tairserver must have their own "mdb_shm_path" # # mdb_shm_path=/mdb_shm_path02 #tairserver listen port port=5192 heartbeat_port=6192 process_thread_num=16 # #mdb size in MB # slab_mem_size=1024 log_file=/root/tair_bin_ds2/logs/server.log pid_file=/root/tair_bin_ds2/logs/server.pid log_level=warn dev_name=eth1 ulog_dir=/root/tair_bin_ds2/data/ulog ulog_file_number=3 ulog_file_size=64 check_expired_hour_range=2-4 check_slab_hour_range=5-7 dup_sync=1 do_rsync=0 # much resemble json format # one local cluster config and one or multi remote cluster config. # {local:[master_cs_addr,slave_cs_addr,group_name,timeout_ms,queue_limit],remote:[...],remote:[...]} rsync_conf={local:[10.0.0.1:5198,10.0.0.2:5198,group_local,2000,1000],remote:[10.0.1.1:5198,10.0.1.2:5198,group_remote,2000,3000]} # if same data can be updated in local and remote cluster, then we need care modify time to # reserve latest update when do rsync to each other. rsync_mtime_care=0 # rsync data directory(retry_log/fail_log..) rsync_data_dir=/root/tair_bin_ds2/data/remote # max log file size to record failed rsync data, rotate to a new file when over the limit rsync_fail_log_size=30000000 # whether do retry when rsync failed at first time rsync_do_retry=0 # when doing retry, size limit of retry log's memory use rsync_retry_log_mem_size=100000000 [fdb] # in MB index_mmap_size=30 cache_size=256 bucket_size=10223 free_block_pool_size=8 data_dir=/root/tair_bin_ds2/data/fdb fdb_name=tair_fdb [kdb] # in byte map_size=10485760 # the size of the internal memory-mapped region bucket_size=1048583 # the number of buckets of the hash table record_align=128 # the power of the alignment of record size data_dir=/root/tair_bin_ds2/data/kdb # the directory of kdb's data [ldb] #### ldb manager config ## data dir prefix, db path will be data/ldbxx, "xx" means db instance index. ## so if ldb_db_instance_count = 2, then leveldb will init in ## /data/ldb1/ldb/, /data/ldb2/ldb/. We can mount each disk to ## data/ldb1, data/ldb2, so we can init each instance on each disk. data_dir=/root/tair_bin_ds2/data/ldb ## leveldb instance count, buckets will be well-distributed to instances ldb_db_instance_count=1 ## whether load backup version when startup. ## backup version may be created to maintain some db data of specifid version. ldb_load_backup_version=0 ## whether support version strategy. ## if yes, put will do get operation to update existed items's meta info(version .etc), ## get unexist item is expensive for leveldb. set 0 to disable if nobody even care version stuff. ldb_db_version_care=1 ## time range to compact for gc, 1-1 means do no compaction at all ldb_compact_gc_range = 3-6 ## backgroud task check compact interval (s) ldb_check_compact_interval = 120 ## use cache count, 0 means NOT use cache,`ldb_use_cache_count should NOT be larger ## than `ldb_db_instance_count, and better to be a factor of `ldb_db_instance_count. ## each cache mdb's config depends on mdb's config item(mdb_type, slab_mem_size, etc) ldb_use_cache_count=1 ## cache stat can't report configserver, record stat locally, stat file size. ## file will be rotate when file size is over this. ldb_cache_stat_file_size=20971520 ## migrate item batch size one time (1M) ldb_migrate_batch_size = 3145728 ## migrate item batch count. ## real batch migrate items depends on the smaller size/count ldb_migrate_batch_count = 5000 ## comparator_type bitcmp by default # ldb_comparator_type=numeric ## numeric comparator: special compare method for user_key sorting in order to reducing compact ## parameters for numeric compare. format: [meta][prefix][delimiter][number][suffix] ## skip meta size in compare # ldb_userkey_skip_meta_size=2 ## delimiter between prefix and number # ldb_userkey_num_delimiter=: #### ## use blommfilter ldb_use_bloomfilter=1 ## use mmap to speed up random acess file(sstable),may cost much memory ldb_use_mmap_random_access=0 ## how many highest levels to limit compaction ldb_limit_compact_level_count=0 ## limit compaction ratio: allow doing one compaction every ldb_limit_compact_interval ## 0 means limit all compaction ldb_limit_compact_count_interval=0 ## limit compaction time interval ## 0 means limit all compaction ldb_limit_compact_time_interval=0 ## limit compaction time range, start == end means doing limit the whole day. ldb_limit_compact_time_range=6-1 ## limit delete obsolete files when finishing one compaction ldb_limit_delete_obsolete_file_interval=5 ## whether trigger compaction by seek ldb_do_seek_compaction=0 ## whether split mmt when compaction with user-define logic(bucket range, eg) ldb_do_split_mmt_compaction=0 #### following config effects on FastDump #### ## when ldb_db_instance_count > 1, bucket will be sharded to instance base on config strategy. ## current supported: ## hash : just do integer hash to bucket number then module to instance, instance's balance may be ## not perfect in small buckets set. same bucket will be sharded to same instance ## all the time, so data will be reused even if buckets owned by server changed(maybe cluster has changed), ## map : handle to get better balance among all instances. same bucket may be sharded to different instance based ## on different buckets set(data will be migrated among instances). ldb_bucket_index_to_instance_strategy=map ## bucket index can be updated. this is useful if the cluster wouldn't change once started ## even server down/up accidently. ldb_bucket_index_can_update=1 ## strategy map will save bucket index statistics into file, this is the file's directory ldb_bucket_index_file_dir=/root/tair_bin_ds2/data/bindex ## memory usage for memtable sharded by bucket when batch-put(especially for FastDump) ldb_max_mem_usage_for_memtable=3221225472 #### #### leveldb config (Warning: you should know what you're doing.) ## one leveldb instance max open files(actually table_cache_ capacity, consider as working set, see `ldb_table_cache_size) ldb_max_open_files=65535 ## whether return fail when occure fail when init/load db, and ## if true, read data when compactiong will verify checksum ldb_paranoid_check=0 ## memtable size ldb_write_buffer_size=67108864 ## sstable size ldb_target_file_size=8388608 ## max file size in each level. level-n (n > 0): (n - 1) * 10 * ldb_base_level_size ldb_base_level_size=134217728 ## sstable's block size # ldb_block_size=4096 ## sstable cache size (override `ldb_max_open_files) ldb_table_cache_size=1073741824 ##block cache size ldb_block_cache_size=16777216 ## arena used by memtable, arena block size #ldb_arenablock_size=4096 ## key is prefix-compressed period in block, ## this is period length(how many keys will be prefix-compressed period) # ldb_block_restart_interval=16 ## specifid compression method (snappy only now) # ldb_compression=1 ## compact when sstables count in level-0 is over this trigger ldb_l0_compaction_trigger=1 ## write will slow down when sstables count in level-0 is over this trigger ## or sstables' filesize in level-0 is over trigger * ldb_write_buffer_size if ldb_l0_limit_write_with_count=0 ldb_l0_slowdown_write_trigger=32 ## write will stop(wait until trigger down) ldb_l0_stop_write_trigger=64 ## when write memtable, max level to below maybe ldb_max_memcompact_level=3 ## read verify checksum ldb_read_verify_checksums=0 ## write sync log. (one write will sync log once, expensive) ldb_write_sync=0 ## bits per key when use bloom filter #ldb_bloomfilter_bits_per_key=10 ## filter data base logarithm. filterbasesize=1<<ldb_filter_base_logarithm #ldb_filter_base_logarithm=12
4）至此2台 Data Server 也配置完畢
四、啟動Tair Server集群
1、通過終端任意選其中一台Server執行 set_shm.sh（需要root權限），修改系統分配內存策略，確保程序能夠使用足夠的共享內存
命令： “ ./set_shm.sh ”
2、分別通過終端進入2台Data Server目錄，執行 tair.sh 腳本啟動服務器，注意：請先啟動DataServer，后啟動ConfigServer，相關解釋見wiki
此時由於Config Server還沒有啟動，Log會出現heartbeat錯誤。
[2014-12-19 19:28:42.336703] ERROR handlePacket (heartbeat_thread.cpp:141) [140335215126272] ControlPacket, cmd:3
[2014-12-19 19:28:43.341952] ERROR handlePacket (heartbeat_thread.cpp:141) [140335215126272] ControlPacket, cmd:2 [2014-12-19 19:28:43.341982] ERROR handlePacket (heartbeat_thread.cpp:141) [140335215126272] ControlPacket, cmd:3 [2014-12-19 19:28:44.345308] WARN update_server_table (tair_manager.cpp:1397) [140334767929088] updateServerTable, size: 2046 [2014-12-19 19:28:44.345312] WARN handlePacket (heartbeat_thread.cpp:212) [140335215126272] config server HOST UP: 10.0.2.15:5198 [2014-12-19 19:28:44.345350] WARN handlePacket (heartbeat_thread.cpp:212) [140335215126272] config server HOST UP: 10.0.2.15:5200
命令： “ ./tair.sh start_ds ”
3、分別通過終端進入2台Config Server目錄，通過執行 tair.sh 腳本來啟動服務器
命令： “ ./tair.sh start_cs ”
4、至此4台服務器啟動完畢，過程不會一帆風順，請耐心仔細，查閱log文件
五、客戶端連接Tair Server
1、連接Tair服務器目前有3種方式：命令行、C++版本TairClient、Java版本TairClient（從依賴包可以看出使用的Mina通信框架），
底層使用socket通信，所以理論上只要支持socket操作的程序語言都可以直接實現Tair客戶端
2、通過終端進入任意一個Server程序目錄的 sbin 文件夾，執行 tairclient 命令連接Tair服務器，-c參數表示連接configserver，-s參數表示連接dataserver，
參照下圖命令連接，“group_1” 是group.conf配置文件中的默認值。
連接到 tair configserver 后可以通過 put命令 新增一個鍵值對，例如：put key1 hellowold，然后通過get命令取值，如下圖：
也可以連接到tair dataserver后可以查看單獨某個ds上的數據，下圖可以看出當連接到Port=5191的DataServer可以取到key1的值，5192的DS上則不能取到值。
Tair ConfigServer負載均衡采用一致性哈希算法進行數據分配，更多相關內容請查閱wiki。
六、更多
至此Tair服務器安裝部署完畢，更多關於學習、整合、測試相關的內容請期待后續博文，同時也歡迎有興趣的人交流溝通。