Oracle database installed on the Ali Cloud, one day received the following alerts:
Name=atabasename
Type=database Instance
Host=izw2519p6r9uzeee
Metric=status
Timestamp=nov, 2014 4:16:37 AM CST
Severity=critical
message=failed to connect to database Instance:ora-12519:tns:no appropriate service handler found (DBD Error:ociservera Ttach).
Rule name=database availability and Critical States
Rule Owner=sysman
The reason for this problem is that the number of processes exceeds the limit and is queried by the following methods:
# su-oracle
$ sqlplus/as sysdba;
To view the current number of connections:
Sql> Select COUNT (*) from v$process;
View the current number of connections to 299
To view the maximum number of connections allowed for a database:
Sql> Select value from v$parameter where name = ' processes ';
View the maximum number of connections allowed is 300
It seems that the number of connections is not enough to make the following modifications:
Modify the maximum number of connections to 500:
Sql> alter system set processes = Scope = SPFile;
To restart the database:
sql> shutdown immediate;
Sql> startup;