1、工作流程分析

步驟說明：

1、 Cli接收到用戶的輸入後，對命令進行解析，判斷命令是否合法（命令格式，字符拼寫等檢查），然後RPC調用本機的glusterd程序的遠程函數，glusterd程序開始解析addbrick的命令行，判斷裏面的hostname所對應機器是否存在；peer內的uuid是否存在；brick所對應的路徑是否存在；檢查所對應的brick是否已經存在，日誌片段如下：

[glusterd-op-sm.c:8544:glusterd_op_set_cli_op] 0-: Returning 0

[glusterd-handler.c:1306:glusterd_handle_add_brick] 0-glusterd: Receiv

[glusterd-utils.c:847:glusterd_volinfo_find] 0-: Volume test found

[glusterd-utils.c:855:glusterd_volinfo_find] 0-: Returning 0

[glusterd-utils.c:630:glusterd_brickinfo_new] 0-: Returning 0

[glusterd-utils.c:687:glusterd_brickinfo_from_brick] 0-: Returning 0

[glusterd-utils.c:2755:glusterd_friend_find_by_hostname] 0-glusterd: U

[glusterd-utils.c:211:glusterd_is_local_addr] 0-glusterd: sdc0 is loca

[glusterd-utils.c:2789:glusterd_hostname_to_uuid] 0-: returning 0

[glusterd-utils.c:642:glusterd_resolve_brick] 0-: Returning 0

[glusterd-utils.c:760:glusterd_volume_brickinfo_get] 0-: Returning -1

[glusterd-utils.c:2927:glusterd_new_brick_validate] 0-: returning 0

[glusterd-utils.c:760:glusterd_volume_brickinfo_get] 0-: Returning -1

[glusterd-utils.c:630:glusterd_brickinfo_new] 0-: Returning 0

[glusterd-utils.c:687:glusterd_brickinfo_from_brick] 0-: Returning 0

[glusterd-utils.c:2707:glusterd_friend_find_by_hostname] 0-glusterd: F

[glusterd-utils.c:2789:glusterd_hostname_to_uuid] 0-: returning 0

[glusterd-utils.c:642:glusterd_resolve_brick] 0-: Returning 0

[glusterd-utils.c:2666:glusterd_friend_find_by_uuid] 0-glusterd: Frien

[glusterd-utils.c:760:glusterd_volume_brickinfo_get] 0-: Returning -1

[glusterd-utils.c:2927:glusterd_new_brick_validate] 0-: returning 0

[glusterd-utils.c:760:glusterd_volume_brickinfo_get] 0-: Returning -1

2、對所有機器上的該捲進行加鎖，每臺機器加鎖成功纔算加鎖成功；每個主機的glusterd進程維護了一個全局變量lock，這是該主機的鎖，當加鎖的時候，會判斷lock.owner變量值，0代表沒有加鎖，沒有加鎖的時候，加鎖才能夠成功。首先是本機加鎖，加鎖成了，然後再發送信息給其他的主機進行加鎖。

glusterd-utils.c:243:glusterd_lock] 0-glusterd: Cluster lock held by f0481376-8cee-4eba-a4c2-4790b5eae856

glusterd-handler.c:420:glusterd_op_txn_begin] 0-glusterd: Acquired local lock

glusterd-op-sm.c:8393:glusterd_op_sm_inject_event] 0-glusterd: Enqueuing event: 'GD_OP_EVENT_START_LOCK'

glusterd-handler.c:424:glusterd_op_txn_begin] 0-glusterd: Returning 0

glusterd-op-sm.c:8449:glusterd_op_sm] 0-: Dequeued event of type: 'GD_OP_EVENT_START_LOCK'

glusterd-rpc-ops.c:1541:glusterd3_1_cluster_lock] 0-glusterd: Returning 0

glusterd-op-sm.c:6462:glusterd_op_ac_send_lock] 0-: Returning with 0

glusterd-utils.c:3182:glusterd_sm_tr_log_transition_add] 0-glusterd: Transitioning from 'Default' to 'Lock sent' due to event 'GD_OP_EVENT_START_LOCK'

glusterd-utils.c:3184:glusterd_sm_tr_log_transition_add] 0-: returning 0

glusterd-utils.c:577:glusterd_volume_brickinfos_delete] 0-: Returning 0

glusterd-rpc-ops.c:759:glusterd3_1_cluster_lock_cbk] 0-glusterd: Received ACC from uuid: cb2b0881-831f-4c28-8e4e-e4f1bd01e842

3、清除一些brick信息，刪除一些時間戳的臨時文件；

4、啓動添加的brick進程；

5、以執行該命令的機器作爲第一臺機器，然後第一臺機器創建卷目錄，及其相關的所有的brick文件，並且將內存裏面的卷，brick相關信息寫入到相應的文件內；第一臺機器完成這些操作後，第二臺機器重複該操作。。。。。第一臺機器收到這些節點信息修改的成功響應後纔算成功；