我试图在四个EC2 t2.2xlarge节点上建立一个Cassandra cluter，其中一个节点被提名为种子。群集似乎已在每个节点上启动。但是，当我尝试运行/ opt / cassandra / bin / cqlsh时，我收到以下错误：
Connection error: ('Unable to connect to any servers', {'127.0.0.1': error(111, "Tried connecting to [('127.0.0.1', 9042)]. Last error: Connection refused")})
当我在种子节点上对9042执行netstat时，我得到以下输出：
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 ip-172-xx-xx-111.eu-wes:9042 *:* LISTEN
我认为这个主机地址可能是问题的根源，但不知道如何设置它，或者如何更改它。它应该是127.0.0.1还是localhost？
我有一个安全组设置，其中包含端口9042的以下信息：
Type Protocol Port Range Source
-------------------------------------------------------------------------
Custom TCP Rule TCP 9042 sg-<group-id> (<group-name>)
也许这里的来源是错的？这应该是localhost或什么？
以下是我在每个节点上更改的cassandra.yaml中的值：
listen_interface: eth0
broadcast_address: <local-PRIVATE-ip>
rpc_address: <local-PRIVATE-ip>
seed_provider:
# Addresses of hosts that are deemed contact points.
# Cassandra nodes use this list of hosts to find each other and learn
# the topology of the ring. You must change this if you are running
# multiple nodes!
- class_name: org.apache.cassandra.locator.SimpleSeedProvider
parameters:
# seeds is actually a comma-delimited list of addresses.
# Ex: "<ip1>,<ip2>,<ip3>"
- seeds: "<seed-node-PRIVATE-ip>"
当我启动每个节点时，日志中的最终消息是：
INFO 11:32:44 Node /172.xx.xx.222 state jump to NORMAL
INFO 11:32:44 Waiting for gossip to settle before accepting client requests...
INFO 11:32:44 Compacted 4 sstables to [/var/lib/cassandra/data/system/local-7ad54392bcdd35a684174e047860b377/system-local-ka-13,]. 11,190 bytes to 5,773 (~51% of original) in 24ms = 0.229398MB/s. 4 total partitions merged to 1. Partition merge counts were {4:1, }
INFO 11:32:52 No gossip backlog; proceeding
种子节点日志的最后几行是：
INFO 11:58:35 Enqueuing flush of local: 578 (0%) on-heap, 0 (0%) off-heap
INFO 11:58:35 Writing Memtable-local@1006553205(0.081KiB serialized bytes, 4 ops, 0%/0% of on/off-heap limit)
INFO 11:58:35 Completed flushing /var/lib/cassandra/data/system/local-7ad54392bcdd35a684174e047860b377/system-local-tmp-ka-14-Data.db (0.000KiB) for commitlog position ReplayPosition(segmentId=1550836714360, position=94125)
INFO 11:58:35 Handshaking version with /172.xx.xx.222
INFO 11:58:35 Node /172.xx.xx.333 has restarted, now UP
INFO 11:58:35 Handshaking version with /172.xx.xx.333
INFO 11:58:35 Node /172.xx.xx.333 state jump to NORMAL
INFO 11:58:35 Enqueuing flush of local: 51462 (0%) on-heap, 0 (0%) off-heap
INFO 11:58:35 Writing Memtable-local@961534831(8.349KiB serialized bytes, 259 ops, 0%/0% of on/off-heap limit)
INFO 11:58:35 Completed flushing /var/lib/cassandra/data/system/local-7ad54392bcdd35a684174e047860b377/system-local-tmp-ka-15-Data.db (0.000KiB) for commitlog position ReplayPosition(segmentId=1550836714360, position=106779)
INFO 11:58:35 InetAddress /172.xx.xx.333 is now UP
INFO 11:58:35 Node /172.xx.xx.111 state jump to NORMAL
INFO 11:58:35 Updating topology for /172.xx.xx.333
INFO 11:58:35 Updating topology for /172.xx.xx.333
INFO 11:58:35 Node /172.xx.xx.444 has restarted, now UP
INFO 11:58:35 Waiting for gossip to settle before accepting client requests...
INFO 11:58:35 Node /172.xx.xx.444 state jump to NORMAL
INFO 11:58:35 Handshaking version with /172.xx.xx.444
INFO 11:58:35 InetAddress /172.xx.xx.444 is now UP
INFO 11:58:35 Updating topology for /172.xx.xx.444
INFO 11:58:35 Updating topology for /172.xx.xx.444
INFO 11:58:35 Node /172.xx.xx.222 has restarted, now UP
INFO 11:58:35 Node /172.xx.xx.222 state jump to NORMAL
INFO 11:58:35 InetAddress /172.xx.xx.222 is now UP
INFO 11:58:35 Updating topology for /172.xx.xx.222
INFO 11:58:35 Updating topology for /172.xx.xx.222
INFO 11:58:38 Updating topology for all endpoints that have changed
INFO 11:58:43 No gossip backlog; proceeding
因此，其他非种子节点（172.xx.xx.222/333/444）的每个IP似乎都被报告为UP。种子节点（172.xx.xx.111）只报告为state jump to NORMAL。
Connection error: ('Unable to connect to any servers', {'127.0.0.1': error(111, "Tried connecting to [('127.0.0.1', 9042)]. Last error: Connection refused")})
看起来您正在尝试通过CQLSH连接到127.0.0.1，这在多个节点集群中不起作用。使用您的凭据指定确切的（广播）IP，它应该允许您进入。
例如：
$ grep _address conf/cassandra.yaml | grep -v "#"
listen_address: 192.168.1.4
broadcast_address: 10.1.3.6
rpc_address: 192.168.1.4
broadcast_rpc_address: 10.1.3.6
$ bin/cqlsh 10.1.3.6 -u flynn -p reindeerFlotilla
Connected to AaronTest at 10.1.3.6:9042.
[cqlsh 5.0.1 | Cassandra 3.11.2 | CQL spec 3.4.4 | Native protocol v4]
Use HELP for help.
flynn@cqlsh>