UTC Sending warning alert CloseNotify

[stone212]

Before filing a new issue, please provide the following information.

I'm running:

• Which Parity version?: v1.10.7-stable
• Which operating system?: Ubuntu 16.04
• How installed?: via binaries
• Are you fully synchronized?: yes
• Which network are you connected to?: ethereum (foundation)
• Did you try to restart the node?: yes

Your issue description goes here below. Try to include actual vs. expected behavior and steps to reproduce the issue.

A possibly incorrect user bug report made me to check a long-running Parity node with open ports 30303 and 30304/udp I restarted the node and looked at Parity output and it looked very healthy (30/50 peers). After some time I saw that Parity-UI could not make a test transaction because there were not enough peers. The console output showed a "CloseNotify" alert.

I do not understand this in the context of Parity. Please see how connectivity was good. Then the alert happened. Then the node started connecting to peers from 1/25. I do not know if the connectivity and the CloseNotify alerts are related but they happened at the same time.

2018-07-02 09:28:47 UTC Imported #5891691 4af8…e101 (53 txs, 7.97 Mgas, 213.72 ms, 19.26 KiB)
2018-07-02 09:28:52 UTC Imported #5891692 9131…fed5 (24 txs, 7.14 Mgas, 427.10 ms, 14.17 KiB)
2018-07-02 09:28:56 UTC   27/50 peers   580 KiB chain 70 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  7 req/s, 236 µs
2018-07-02 09:31:41 UTC Sending warning alert CloseNotify
2018-07-02 09:31:49 UTC Sending warning alert CloseNotify
2018-07-02 09:31:51 UTC Imported #5891694 4334…f091 (17 txs, 7.99 Mgas, 264.81 ms, 12.10 KiB) + another 1 block(s) containing 19 tx(s)
2018-07-02 09:31:59 UTC    1/25 peers   3 MiB chain 70 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  9 req/s, 481 µs
2018-07-02 09:31:59 UTC    1/25 peers   3 MiB chain 70 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  9 req/s, 481 µs
2018-07-02 09:31:59 UTC    1/25 peers   3 MiB chain 70 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  9 req/s, 481 µs

Moments later the connectivity was 16/25 and I could send a test transaction.

Moments after this the CloseNotify error returned many times. Peer connections fluctuate between 7-30. Here is more output that might help:

iB sync  RPC:  1 conn,  8 req/s, 225 µs
2018-07-02 09:43:17 UTC Imported #5891759 dc3a…5311 (16 txs, 7.99 Mgas, 583.97 ms, 17.88 KiB) + another 1 block(s) containing 52 tx(s)
2018-07-02 09:43:54 UTC    7/25 peers   5 MiB chain 70 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  1 req/s, 158 µs
2018-07-02 09:43:54 UTC    7/25 peers   5 MiB chain 70 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  1 req/s, 158 µs
2018-07-02 09:43:54 UTC    7/25 peers   5 MiB chain 70 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  2 req/s, 158 µs
2018-07-02 09:43:54 UTC    7/25 peers   5 MiB chain 70 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  2 req/s, 158 µs
2018-07-02 09:44:27 UTC    7/25 peers   5 MiB chain 70 MiB db 0 bytes queue 35 KiB sync  RPC:  1 conn,  1 req/s, 166 µs
2018-07-02 09:44:28 UTC    5/25 peers   5 MiB chain 70 MiB db 0 bytes queue 35 KiB sync  RPC:  1 conn,  1 req/s, 166 µs
2018-07-02 09:44:44 UTC Imported #5891763 a760…49eb (119 txs, 7.98 Mgas, 861.44 ms, 23.71 KiB)
2018-07-02 09:45:02 UTC   16/25 peers   6 MiB chain 71 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  1 req/s, 206 µs
2018-07-02 09:45:20 UTC Imported #5891769 1862…8745 (110 txs, 7.99 Mgas, 1033.74 ms, 19.29 KiB) + another 3 block(s) containing 114 tx(s)
2018-07-02 09:45:28 UTC Imported #5891770 c65a…8e7c (52 txs, 7.99 Mgas, 465.73 ms, 22.94 KiB)
2018-07-02 09:45:32 UTC Sending warning alert CloseNotify
2018-07-02 09:45:34 UTC Imported #5891769 42d5…e0d9 (36 txs, 8.00 Mgas, 331.45 ms, 22.00 KiB)
2018-07-02 09:45:40 UTC Imported #5891772 ee26…97da (77 txs, 7.93 Mgas, 385.38 ms, 18.16 KiB)
2018-07-02 09:45:46 UTC Imported #5891772 8a85…0ac0 (25 txs, 7.99 Mgas, 335.23 ms, 13.94 KiB)
2018-07-02 09:45:55 UTC   21/25 peers   0 bytes chain 71 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  6 req/s, 256 µs
2018-07-02 09:46:05 UTC Imported #5891772 9957…029c (21 txs, 8.00 Mgas, 311.87 ms, 13.87 KiB)
2018-07-02 09:46:11 UTC Imported #5891773 6540…7fb3 (44 txs, 7.93 Mgas, 141.44 ms, 11.06 KiB)
2018-07-02 09:46:35 UTC   20/25 peers   3 MiB chain 71 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  6 req/s, 190 µs
2018-07-02 09:46:35 UTC   20/25 peers   3 MiB chain 71 MiB db 0 bytes queue 32 KiB sync  RPC:  1 conn,  6 req/s, 190 µs
2018-07-02 09:46:40 UTC Reorg to #5891774 daa2…4005 (6540…7fb3 #5891772 ee26…97da cdd6…8c03)

[Tbaut]

The message "Sending warning alert CloseNotify" is actually an indication that peers got disconnected. It is in this case, it is, therefore, the consequence, not the cause of disconnections (There is BTW a PR to hide it as irrelevant for the end user #9025).

This problem of peer disconnection should be solved in 1.11, please give it a try.