在具有資料庫 HA 組態的 VMware Cloud Director 應用裝置部署中，postgres 使用者無法透過 SSH 連線至其對等資料庫節點。
問題
當資料庫節點之間出現 SSH 問題時，VMware Cloud Director 會顯示 localClusterHealth 為 SSH_PROBLEM。必須盡快修正此嚴重問題。
可以使用 VMware Cloud Director 應用裝置管理使用者介面來檢視 localClusterHealth，也可以執行 /nodes VMware Cloud Director 應用裝置 API。請參閱 VMware Cloud Director 應用裝置 API 說明文件。
在出現 SSH 問題的某個節點的對等節點上執行 /nodes API 時，/nodes API 會傳回以下資訊：localClusterHealth 為 SSH_PROBLEM，localClusterFailover 為 INDETERMINATE。容錯移轉模式為 INDETERMINATE，因為執行 /nodes API 的節點無法透過 SSH 連線到其對等節點之一。對於出現 SSH 問題的節點，其回應本文的 "failover" 輸出部分中的 "details" 顯示：ssh failed.command: ssh unreachable_standby_host_IP /usr/bin/grep failover=manual /opt/vmware/vpostgres/10/etc/repmgr.conf。
GET https://primary_host_IP:5480/api/1.0.0/nodes，則
/nodes API 可能會傳回下列資訊。
{
"localClusterFailover": "INDETERMINATE",
"localClusterHealth": "SSH_PROBLEM",
"localClusterState": [
{
"connectionString": "host=primary_host_IP user=repmgr dbname=repmgr connect_timeout=2",
"failover": {
"details": "failover = manual",
"mode": "MANUAL",
"repmgrd": {
"details": "On node primary_node_ID (primary_host_name): repmgrd = not applicable",
"status": "NOT APPLICABLE"
}
},
"id": primary_node_ID,
"location": "default",
"name": "primary_host_name",
"nodeHealth": "HEALTHY",
"nodeRole": "PRIMARY",
"role": "primary",
"status": "* running",
"upstream": ""
},
{
"connectionString": "host=running_standby_host_IP user=repmgr dbname=repmgr connect_timeout=2",
"failover": {
"details": "failover = manual",
"mode": "MANUAL",
"repmgrd": {
"details": "On node running_standby_node_ID (running_standby_host_name): repmgrd = not applicable",
"status": "NOT APPLICABLE"
}
},
"id": running_standby_node_ID,
"location": "default",
"name": "running_standby_host_name",
"nodeHealth": "HEALTHY",
"nodeRole": "STANDBY",
"role": "standby",
"status": "running",
"upstream": "primary_host_name"
},
{
"connectionString": "host=unreachable_standby_host_IP user=repmgr dbname=repmgr connect_timeout=2",
"failover": {
"details": "ssh failed. command: ssh unreachable_standby_host_IP /usr/bin/grep failover=manual /opt/vmware/vpostgres/10/etc/repmgr.conf",
"mode": "UNKNOWN",
"repmgrd": {
"details": "On node unreachable_standby_node_ID (unreachable_standby_host_name): repmgrd = not running",
"status": "NOT RUNNING"
}
},
"id": unreachable_standby_node_ID,
"location": "default",
"name": "unreachable_standby_host_name",
"nodeHealth": "HEALTHY",
"nodeRole": "STANDBY",
"role": "standby",
"status": "running",
"upstream": "primary_host_name"
}
],
"warnings": []
}
如果執行 GET https://unreachable_standby_host_IP:5480/api/1.0.0/nodes，由於節點不受信任，則 localClusterFailover 和 localClusterState 資訊可能不正確。/nodes API 傳回警告訊息，指出 unreachable_standby_host_name 無法連線至其對等節點。
/nodes API 可能會傳回下列資訊。
{
"localClusterFailover": "MANUAL",
"localClusterHealth": "SSH_PROBLEM",
"localClusterState": [
{
"connectionString": "host=primary_host_IP user=repmgr dbname=repmgr connect_timeout=2",
"failover": {
"details": "ssh failed. command: ssh primary_host_IP /usr/bin/grep failover=manual /opt/vmware/vpostgres/10/etc/repmgr.conf",
"mode": "UNKNOWN",
"repmgrd": {
"details": "On node primary_node_ID (primary_host_name): repmgrd = n/a",
"status": "UNKNOWN"
}
},
"id": primary_node_ID,
"location": "default",
"name": "primary_host_name",
"nodeHealth": "UNHEALTHY",
"nodeRole": "PRIMARY",
"role": "primary",
"status": "? running",
"upstream": ""
},
{
"connectionString": "host=running_standby_host_IP user=repmgr dbname=repmgr connect_timeout=2",
"failover": {
"details": "ssh failed. command: ssh running_standby_host_IP /usr/bin/grep failover=manual /opt/vmware/vpostgres/10/etc/repmgr.conf",
"mode": "UNKNOWN",
"repmgrd": {
"details": "On node running_standby_node_ID (running_standby_host_name): repmgrd = n/a",
"status": "UNKNOWN"
}
},
"id": running_standby_node_ID,
"location": "default",
"name": "running_standby_host_name",
"nodeHealth": "UNHEALTHY",
"nodeRole": "STANDBY",
"role": "standby",
"status": "? running",
"upstream": "primary_host_name"
},
{
"connectionString": "host=unreachable_standby_host_IP user=repmgr dbname=repmgr connect_timeout=2",
"failover": {
"details": "failover = manual",
"mode": "MANUAL",
"repmgrd": {
"details": "On node unreachable_standby_node_ID (unreachable_standby_host_name): repmgrd = not applicable",
"status": "NOT APPLICABLE"
}
},
"id": unreachable_standby_node_ID,
"location": "default",
"name": "unreachable_standby_host_name",
"nodeHealth": "HEALTHY",
"nodeRole": "STANDBY",
"role": "standby",
"status": "running",
"upstream": "? primary_host_name"
}
],
"warnings": [
"unable to connect to node \"primary_host_name\" (ID: primary_node_ID)",
"unable to connect to node \"running_standby_host_name\" (ID: running_standby_node_ID)",
"unable to connect to node \"unreachable_standby_host_name\" (ID: unreachable_standby_node_ID)'s upstream node \"primary_host_name\" (ID: primary_node_ID)",
"unable to determine if node \"unreachable_standby_host_name\" (ID: unreachable_standby_node_ID) is attached to its upstream node \"primary_host_name\" (ID: primary_node_ID)"
]
}
原因
VMware Cloud Director 將 postgres 使用者的 SSH 憑證儲存在 NFS 共用傳輸伺服器儲存區中。所有資料庫節點都必須具有共用傳輸伺服器儲存區的存取權。如果資料庫節點變得不受信任，即 postgres 使用者的 SSH 憑證不再有效或無法再存取，則該節點無法使用 SSH 用戶端在其對等節點上執行命令。VMware Cloud Director 應用裝置必須具有此功能，才能在 HA 模式下正確執行。
