Error persistence.

If there is an exception when trying to persist data into storage. Cygnus is capable to store it into a new table as long as there is successful connection to persistence manager.

This only applies to SQL type backends PostgreSQL & MySQL. Notice that Postgis uses PostgreSQL backend so this function extends to Postgis as well as PostgreSQL and MySQL.

As mentioned before, if there is an exception when trying to persist data, Cygnus tryes to create a table with the following pattern.

$databaseName_error_log

with the following scheme.

Column name	SQL Type
timestamp	TIMESTAMP
error	TEXT
query	TEXT

For instance.

If Cygnus receives a request that attemp to execute the query:

INSERT INTO prueba2.streetlight (recvT
ime,fiwareServicePath,entityId,entityType,TimeInstant,TimeInstant_md,serialNumber,serialNumber_md) VALUES ('2020-02-27 09:12:29.344','/e','farolahttpu
l','Streetlight','2019-10-31T13:49:17.00Z','[]','OP00096F160318C000004','[]'),('2020-02-27 09:12:30.510','/e','farolahttpul','Streetlight','2019-10-31
T13:49:17.00Z','[]','OP00096F160318C000004','[]')

But the table streetlight doesn't exists, then this will produce a SQL Exception;

ERROR: relation "prueba2.streetlight" does not exist

Then Cygnus will create a table:

prueba2_error_log

And finally execute a query to insert the exception into the new table.

2020-02-27 09:12:42.049 | ERROR: relation "prueba2.streetlight" does not exist+| INSERT INTO prueba2.streetlight (recvT
ime,fiwareServicePath,entityId,entityType,TimeInstant,TimeInstant_md,serialNumber,serialNumber_md) VALUES ('2020-02-27 09:12:29.344','/e','farolahttpu
l','Streetlight','2019-10-31T13:49:17.00Z','[]','OP00096F160318C000004','[]'),('2020-02-27 09:12:30.510','/e','farolahttpul','Streetlight','2019-10-31
T13:49:17.00Z','[]','OP00096F160318C000004','[]')