Sync failed because the parent block is not found

[majecty]

A node in Corgi failed to validate a block and stopped syncing.

In the log, the node tries to verify the 13433'rd block after 13430'th block.

validator2, ERROR, client, 2019-01-21 16:20:53+09:00 content is Block import failed for #13433 (0x94ee…1c4e): Parent block not found (0x276c…9646)

[majecty]

The node does not have blocks 13431, 13432, and 13433.

kodebox@TEST1:~/codechain-for-corgi$ curl     -H 'Content-Type: application/json'     -d '{"jsonrpc": "2.0", "method": "chain_getBlockByNumber", "params": [13430], "id": null}'     localhost:18080

{"jsonrpc":"2.0","result":{"author":"wccqxr7m59wq06wxqc44xzl323ckac72r6md5wr7dyj","extraData":[],"hash":"0x291484944d0eaa261e5b8e903dfa7883baef381e9485efb020a33c845c7cbe22","invoicesRoot":"0x45b0cfc220ceec5b7c1c62c4d4193d38e4eba48e8815729ce75f9c0ab0e4c1c0","number":13430,"parentHash":"0x011878f4389a9015ea4d06a055245f3e69c89495adc33e3ae1047c318beaa92d","score":"0x3475ffffffffffffffffffffffffffffcb8a","seal":[[1],[128],[249,1,74,184,64,236,128,154,51,124,81,112,201,175,53,203,197,138,184,212,171,215,233,35,192,10,50,216,45,105,142,26,161,122,252,62,69,208,36,211,254,91,115,166,73,205,96,185,193,22,220,127,27,115,38,129,146,2,196,243,109,20,23,19,187,74,58,203,153,184,64,146,112,90,71,16,132,96,144,2,59,215,94,7,127,253,196,190,81,49,233,187,55,129,35,61,79,15,129,235,131,199,212,192,176,137,136,120,105,139,76,252,140,10,154,37,238,2,46,222,158,180,198,53,16,23,79,184,200,64,38,210,135,42,63,184,64,66,168,192,141,42,156,196,167,106,198,134,143,0,224,252,240,176,239,1,254,253,146,255,231,241,165,79,11,4,166,99,78,98,96,255,239,18,231,251,151,122,193,17,73,9,215,98,164,48,56,15,110,252,94,147,137,41,237,122,108,101,110,13,92,184,64,23,153,53,240,114,144,51,148,62,248,155,121,89,179,60,122,107,24,111,57,128,110,174,154,145,196,249,126,177,99,224,205,62,207,180,18,253,26,93,110,203,198,125,153,121,162,117,186,21,123,228,53,12,143,238,205,174,204,224,32,150,63,140,131,184,64,51,97,64,242,165,245,41,19,144,86,31,57,40,82,182,34,244,178,21,61,174,196,164,161,159,10,229,236,101,185,66,133,146,223,87,202,215,167,68,25,140,225,140,38,0,21,129,148,39,239,84,229,42,16,241,151,241,207,191,254,107,180,58,98],[184,100,115,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]],"stateRoot":"0x491f400ec3d3f82986424dfcb12fda4eededa428114e7142598e324d3cdae56a","timestamp":1548053965,"transactions":[],"transactionsRoot":"0x45b0cfc220ceec5b7c1c62c4d4193d38e4eba48e8815729ce75f9c0ab0e4c1c0"},"id":null}

kodebox@TEST1:~/codechain-for-corgi$ curl     -H 'Content-Type: application/json'     -d '{"jsonrpc": "2.0", "method": "chain_getBlockByNumber", "params": [13431], "id": null}'     localhost:18080
{"jsonrpc":"2.0","result":null,"id":null}
kodebox@TEST1:~/codechain-for-corgi$ curl     -H 'Content-Type: application/json'     -d '{"jsonrpc": "2.0", "method": "chain_getBlockByNumber", "params": [13432], "id": null}'     localhost:18080
{"jsonrpc":"2.0","result":null,"id":null}
kodebox@TEST1:~/codechain-for-corgi$ curl     -H 'Content-Type: application/json'     -d '{"jsonrpc": "2.0", "method": "chain_getBlockByNumber", "params": [13433], "id": null}'     localhost:18080
{"jsonrpc":"2.0","result":null,"id":null}
kodebox@TEST1:~/codechain-for-corgi$ curl     -H 'Content-Type: application/json'     -d '{"jsonrpc": "2.0", "method": "chain_getBlockByNumber", "params": [13434], "id": null}'     localhost:18080
{"jsonrpc":"2.0","result":null,"id":null}

[majecty]

I'm suspecting the import_verified_headers function.
The importing order of blocks is decided by the enacted vector in the new_headers function.

[majecty]

I will wait for the error to occur again.