The impact is that it is still in gossip and may still be in your peers.  Node tool status pulls from the snitch, not gossip, so since it was decommissioned it will not show up there.  The only way to remove it from gossip would be to unsafeAssasinate the endpoint.

From: "Zhang, Charles" <Cong.Zhang@fmr.com>
Reply-To: <user@cassandra.apache.org>
Date: Tuesday, May 3, 2016 at 1:09 PM
To: "user@cassandra.apache.org" <user@cassandra.apache.org>
Subject: Decommissioned node shows up in the gossip log

I decommissioned a seed node from the cluster but now it still shows up in the log files but does not show up in “nodetool status”. The steps I took to decommission this seed node was first I added another node to the seed node list and remove this node from the seed node list and then restarted all nodes, and then I used “nodetool decommission” to remove the seed node (which is already not a seed node anymore by this time because I have deleted it from the seed node list). Now when I add a node to the cluster, I can see things like this in the log file:

 

INFO  [GossipStage:1] 2016-05-03 12:47:11,010 Gossiper.java:1010 - InetAddress /10.240.131.52 is now DOWN

INFO  [GossipStage:1] 2016-05-03 12:47:11,013 StorageService.java:2207 - Removing tokens [-1022524973634126820, -1080110197540691971, -1091685779109535219, -1215861550002479909, -1230125663037298110, -1276347863826680388, -1277321492456111075, -1301927496688170836, -1318545134739242389, -1322771136875660408, -1378340458058304278, -1408100110415631237, -1530631940375897404, -1535071782926085329, -1582947345179885144, -16012799486150337, -1696192817763838199, -1728191989986713155, -1745583338734596530, -1826663257009694585, -1851642471126916817, -1857538886064358546, -1901715377875763790, -1932177981591882421, -199072269576364247, -207608666599084705, -2184481684522309754, -2204020999427045206, -2205085893777233579, -2270561486823228034, -2308298192046286704, -235429323779874179, -2463024446587312335, -2495920187667193798, -2500756743826875052, -2506627651269234078, -2514401267607374003, -2545039589436377179, -2634503648039799520, -2646537028163124225, -2683738978574645155, -2807184187110003759, -2867402698030280784, -3114050892122318894, -3206044372292017688, -3281321558107483648, -3385749857713245200, -3416161302882661647, -3506129882816214786, -3513065641380195991, -3535041040510847711, -3613958158418786329, -3648155032806486758, -3665748511643959214, -381185030151387503, -3897484925082811126, -3938608392271975389, -3941659677176701884, -3947462638823321096, -4000556449482859203, -4110196499985462141, -4158458444329621178, -4227086524280114158, -4243909747517318822, -4280784900694217230, -4404716672756332652, -4455430621398252312, -4538061491874241556, -4572589909790935797, -4850346756544186378, -4952456886854152424, -5084536945116622949, -5326752651357993429, -5349130774372022115, -5460653359296793773, -5620302193040734534, -5623709120594154839, -5885389525591890638, -5949589155008107907, -5966013525235445845, -6026141079407570616, -6058868359575464435, -6077630467595631247, -6077845078374374077, -6138431646664499820, -6180882520195395456, -6243210077810081945, -6370284996672456580, -6415049304495129802, -6502707320839506073, -6803145485914681660, -6805877741054487708, -6926104547940671062, -6951403149841557452, -6953035076415327031, -6967464526766340870, -7011060314535843861, -7064863849614017322, -714981435304170064, -7157502981616220702, -7258779025703812914, -7360270914479075946, -73610861802671316, -7563240572942157514, -7635081293483408701, -7798006211363305085, -7813955538719900941, -786373677098356483, -8145051135140174940, -8176945151026682869, -8190382813904504028, -8272254174290282022, -8326684320313230680, -8481234483187517136, -8482289498657787899, -8565844176707815996, -8569487821947184157, -8798368038472556220, -8809438431651729380, -8813359577419549606, -8869977551074344265, -8895973234315752820, -8907908280791280135, -8908127052185996645, -8935928854496370061, -9015683177087077934, -9048056285157467189, -9110697723266307118, -981226497198399669, 1193342841401851448, 1230054248428394457, 1502987728312107227, 1637579501555626797, 1662468220619718905, 1679119062145242310, 1716958612112885132, 1746111140545268100, 1831765078257867905, 1837630369692254413, 1866757535234365933, 1980430493801992453, 2162782596967223630, 2267937126038851741, 2380570386757196663, 2445644030436787439, 2470624736744405884, 2535946784572437079, 2586884334596326732, 261609565442228971, 2807653039695258495, 2820914298989266652, 2850900328012773185, 2856965311103931071, 2878299073894089909, 293663570529846026, 2956982251255851218, 3004636240207923383, 3101507369252962007, 3127101442974941655, 3158812977721178300, 3171231578612039887, 3195192564355682313, 3336607934515052432, 3343357098855461268, 3353820331372189514, 34251354331737275, 3436913366576384630, 3548175524364212676, 3848342826573950162, 3851303454317024860, 3952857562650343132, 3990151331571689362, 4018170568179076035, 4112557911914814333, 4226750948868360216, 4279483569511255118, 4294178225463448329, 4309249284353877565, 4421348708243454111, 4421511311707699441, 4452305848308117645, 4593652086244012593, 4738143394265363235, 4833752378621606367, 4875304341660013392, 4884031847996493712, 4976496196225414573, 5031371703499035791, 5127384657519231924, 5139891720119780283, 5314562593199080390, 5316612914890745425, 5387115956703859037, 5444853543757322231, 5522844729162057439, 5671052167577743873, 5756163457846314224, 5767535292654078271, 5768242158938098694, 5808105469522749152, 5834119627896273386, 5868847068643124331, 5894523213718053689, 5901084982008030187, 5969133132258951572, 5992456767231788605, 6068249796826621917, 6088196406347452820, 6130398062904147944, 626484591742388608, 6308434312037484469, 6339160504017876713, 6355666313243093645, 6562282736963199813, 6565521999605813437, 6576341382108600989, 6594910241855950023, 6657010037537452225, 6732264829847660872, 6750814542377717658, 6752841711698715847, 6753878602599511786, 676331118332583504, 6998945362730848079, 7084036693238869952, 7123724899150065453, 7196754593644784128, 7228947848951386141, 7307770750307662007, 7423504143497361658, 7459372710602518943, 7461980712111448886, 7490521993083116151, 7533000471778287703, 7539331611294816376, 7575124648716146082, 7588493168230482795, 7745663537548315506, 7755819622826291311, 7811819103680710573, 7837217903334494952, 7910337028040730748, 8035987416996982100, 8141008003319228604, 8460970302985166145, 8704724839068075193, 8708181464490295602, 8719281186367503476, 8743407730212179670, 8782996992749946235, 8848834787326682329, 8913871967919712952, 9044250345847868181, 9184734792478964742, 955142821741666815, 998590089428154995] for /10.240.131.52

 

10.240.131.52 is the node I decommissioned and now it does not show up in “nodetool status”…

 

What does this issue impact (assuming this is an issue)? And how should I fix it?

 

Charles