Vertica modifies the maximum number of concurrent connections

Address: http://blog.csdn.net/kongxx/article/details/7176961

During a recent stress test on vertica, we found that the following exception occurs when the number of concurrent requests reaches 50 +.

Com. vertica. util. psqlexception: Fatal: new session rejected due to limit, already 55 sessions active <br/> at com. vertica. core. v3.connectionfactoryimpl. readstartupmessages (unknown source) <br/> at com. vertica. core. v3.connectionfactoryimpl. openconnectionimpl (unknown source) <br/> at com. vertica. core. connectionfactory. openconnection (unknown source) <br/> at com. vertica. jdbc2.abstractjdbc2connection. <init> (unknown source) <br/> at com. vertica. jdbc3.abstractjdbc3connection. <init> (unknown source) <br/> at com. vertica. jdbc3g. jdbc3gconnection. <init> (unknown source) <br/> at com. vertica. driver. makeconnection (unknown source) <br/> at com. vertica. driver. connect (unknown source) <br/> at Org. apache. commons. DBCP. driverconnectionfactory. createconnection (driverconnectionfactory. java: 38) <br/> at Org. apache. commons. DBCP. poolableconnectionfactory. makeobject (poolableconnectionfactory. java: 582) <br/> at Org. apache. commons. pool. impl. genericobjectpool. borrowobject (genericobjectpool. java: 1181) <br/> at Org. apache. commons. DBCP. poolingdatasource. getconnection (poolingdatasource. java: 106) <br/> at Org. apache. commons. DBCP. basicdatasource. getconnection (basicdatasource. java: 1044) <br/> at dbutil. getconnection (dbutil. java: 64) <br/> at dbqueryperformancetest. query (dbqueryperformancetest. java: 46) <br/> at dbqueryperformancetest. access $000 (dbqueryperformancetest. java: 14) <br/> at dbqueryperformancetest$1.exe cute (dbqueryperformancetest. java: 40) <br/> at dbperformancetest. runit (dbperformancetest. java: 97) <br/> at dbperformancetest $ 1.run( dbperformancetest. java: 51) <br/> at java. lang. thread. run (thread. java: 619) <br/> COM. vertica. util. psqlexception: the connection attempt failed. <br/> at com. vertica. core. v3.connectionfactoryimpl. openconnectionimpl (unknown source) <br/> at com. vertica. core. connectionfactory. openconnection (unknown source) <br/> at com. vertica. jdbc2.abstractjdbc2connection. <init> (unknown source) <br/> at com. vertica. jdbc3.abstractjdbc3connection. <init> (unknown source) <br/> at com. vertica. jdbc3g. jdbc3gconnection. <init> (unknown source) <br/> at com. vertica. driver. makeconnection (unknown source) <br/> at com. vertica. driver. connect (unknown source) <br/> at Org. apache. commons. DBCP. driverconnectionfactory. createconnection (driverconnectionfactory. java: 38) <br/> at Org. apache. commons. DBCP. poolableconnectionfactory. makeobject (poolableconnectionfactory. java: 582) <br/> at Org. apache. commons. pool. impl. genericobjectpool. borrowobject (genericobjectpool. java: 1181) <br/> at Org. apache. commons. DBCP. poolingdatasource. getconnection (poolingdatasource. java: 106) <br/> at Org. apache. commons. DBCP. basicdatasource. getconnection (basicdatasource. java: 1044) <br/> at dbutil. getconnection (dbutil. java: 64) <br/> at dbqueryperformancetest. query (dbqueryperformancetest. java: 46) <br/> at dbqueryperformancetest. access $000 (dbqueryperformancetest. java: 14) <br/> at dbqueryperformancetest$1.exe cute (dbqueryperformancetest. java: 40) <br/> at dbperformancetest. runit (dbperformancetest. java: 97) <br/> at dbperformancetest $ 1.run( dbperformancetest. java: 51) <br/> at java. lang. thread. run (thread. (Java: 619) <br/> caused by: java.net. socketexception: Connection Reset <br/> at java.net. socketinputstream. read (socketinputstream. java: 168) <br/> at java. io. bufferedinputstream. fill (bufferedinputstream. java: 218) <br/> at java. io. bufferedinputstream. read (bufferedinputstream. java: 237) <br/> at com. vertica. core. pgstream. receivechar (unknown source) <br/> at com. vertica. core. v3.connectionfactoryimpl. doauthentication (unknown source) <br/>... 19 more <br/>This problem occurs because the maxclientsessions parameter is specified in vertica. You can modify this value using the following SQL statement:

<PRE name = "code" class = "SQL"> select set_config_parameter ('maxclientsession', 250); </PRE> <p>