[pgrouting-users] ERROR: Error computing path: | SQL state: 38001

pgRouting pgrouting-users
1

Hi,

We are developing an web application that users PostgreSQL 8.4 + PostGIS1.5 + Pgrouting 1.03 + development using (Java + Struts + Hibernate)

When this Query is executed:

SELECT ST_AsText(the_geom),id AS Coords FROM delhi_road WHERE id IN (SELECT edge_id FROM shortest_path_astar(‘SELECT id, source, target,x1,y1,x2,y2,cost,reverse_cost from delhi_road’,550,662,true,true))

We are getting the below mentioned error and the other users accessing the application were too facing the database exceptions. Can someone help us to fix this issue.

Error from the postgreSQL query

ERROR: Error computing path:

********** Error **********

ERROR: Error computing path:

SQL state: 38001

Query used:

SELECT ST_AsText(the_geom),id AS Coords FROM delhi_road WHERE id IN (SELECT edge_id FROM shortest_path_astar(‘SELECT id, source, target,x1,y1,x2,y2,cost,reverse_cost from delhi_road’,550,662,true,true))

Error on the Application server (IDE)

[ INFO] 46:48 (MapServiceDAO.java:generateRoute:1525)

Query is…SELECT ST_AsText(the_geom),id AS Coords FROM delhi_road WHERE id IN (SELECT edge_id FROM shortest_path_astar(‘SELECT id, source, target,x1,y1,x2,y2,cost,reverse_cost from delhi_road’,550,662,true,true))

[ INFO] 46:48 (MapServiceDAO.java:generateRoute:1552)

Exception aala…org.postgresql.util.PSQLException: ERROR: Error computing path: _

Feb 22, 2012 11:46:48 AM org.apache.catalina.core.StandardWrapperValve invoke

SEVERE: Servlet.service() for servlet GenerateRoute threw exception

org.hibernate.SessionException: Session was already closed

at org.hibernate.impl.SessionImpl.close(SessionImpl.java:303)

at com.tis.hib.util.HibernateSessionFactory.closeSession(HibernateSessionFactory.java:86)

at com.tis.dao.impl.MapServiceDAO.generateRoute(MapServiceDAO.java:1572)

at com.tis.servlet.GenerateRoute.doGet(GenerateRoute.java:125)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)

at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)

at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)

at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)

at java.lang.Thread.run(Thread.java:619)

Regards,
Palatla Srikanth

2

Palatla,

It is not clear what might be causing this problem. Normally when you get an error on the server there is an error message reported with the error text you got. I just looked at the code and I do not see anyway to generate the error without additional error message. So I'm guessing that maybe the server crashed. This could be because you have multiple copies of the libraries installed or some other system issues. For issues related to the data:

Do you actually have a column "reverse_cost" in the delhi_road table? Is it populated with not NULL values?

How big is this table?
select count(*) from delhi_road;

Typically we use a bbox query on the roads table to select only the roads needed for the solution. Unless this is a small table you should probably change this query to something like:

'SELECT id, source, target,x1,y1,x2,y2,cost,reverse_cost from delhi_road where st_expand(setsrid(makeline(makepoint(xstart,ystart),makepoint(xend,yend)),4326),0.001) && the_geom'

Where xstart, ystart and xend, yend are the xy of the start and end of the route.

4326 is you SRID
0.001 is a small tolerance to expand the bbox by in the units of the geometry column. Pick a number like 500m or the equivalent in degrees.

-Steve

On 2/22/2012 3:40 AM, Palatla Srikanth wrote:

Hi,

We are developing an web application that users PostgreSQL 8.4 +
PostGIS1.5 + Pgrouting 1.03 + development using (Java + Struts + Hibernate)

*When this Query is executed:*

SELECT ST_AsText(the_geom),id AS Coords FROM delhi_road WHERE id IN
(SELECT edge_id FROM shortest_path_astar('SELECT id, source,
target,x1,y1,x2,y2,cost,reverse_cost from delhi_road',550,662,true,true))

We are getting the below mentioned error and the other users accessing
the application were too facing the database exceptions. Can someone
help us to fix this issue.

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

*Error from the postgreSQL query*

ERROR: Error computing path:

********** Error **********

ERROR: Error computing path:

SQL state: 38001

------------------------------------------------------------------------

*Query used:*

**

SELECT ST_AsText(the_geom),id AS Coords FROM delhi_road WHERE id IN
(SELECT edge_id FROM shortest_path_astar('SELECT id, source,
target,x1,y1,x2,y2,cost,reverse_cost from delhi_road',550,662,true,true))

-------------------------------------------------------------------------

*Error on the Application server (IDE)*

[ INFO] 46:48 ( MapServiceDAO.java:generateRoute:1525 )

Query is......SELECT ST_AsText(the_geom),id AS Coords FROM delhi_road
WHERE id IN (SELECT edge_id FROM shortest_path_astar('SELECT id, source,
target,x1,y1,x2,y2,cost,reverse_cost from delhi_road',550,662,true,true))

[ INFO] 46:48 ( MapServiceDAO.java:generateRoute:1552 )

Exception aala.........org.postgresql.util.PSQLException : ERROR: Error
computing path: _

Feb 22, 2012 11:46:48 AM org.apache.catalina.core.StandardWrapperValve
invoke

SEVERE: Servlet.service() for servlet GenerateRoute threw exception

org.hibernate.SessionException : Session was already closed

       at org.hibernate.impl.SessionImpl.close( SessionImpl.java:303 )

       at com.tis.hib.util.HibernateSessionFactory.closeSession(
HibernateSessionFactory.java:86 )

       at com.tis.dao.impl.MapServiceDAO.generateRoute(
MapServiceDAO.java:1572 )

       at com.tis.servlet.GenerateRoute.doGet( GenerateRoute.java:125 )

       at javax.servlet.http.HttpServlet.service( HttpServlet.java:690 )

       at javax.servlet.http.HttpServlet.service( HttpServlet.java:803 )

       at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(
ApplicationFilterChain.java:290 )

       at org.apache.catalina.core.ApplicationFilterChain.doFilter(
ApplicationFilterChain.java:206 )

       at org.apache.catalina.core.StandardWrapperValve.invoke(
StandardWrapperValve.java:230 )

       at org.apache.catalina.core.StandardContextValve.invoke(
StandardContextValve.java:175 )

       at org.apache.catalina.core.StandardHostValve.invoke(
StandardHostValve.java:128 )

       at org.apache.catalina.valves.ErrorReportValve.invoke(
ErrorReportValve.java:104 )

       at org.apache.catalina.core.StandardEngineValve.invoke(
StandardEngineValve.java:109 )

       at org.apache.catalina.connector.CoyoteAdapter.service(
CoyoteAdapter.java:261 )

       at org.apache.coyote.http11.Http11Processor.process(
Http11Processor.java:844 )

       at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(
Http11Protocol.java:581 )

       at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(
JIoEndpoint.java:447 )

       at java.lang.Thread.run( Thread.java:619 )

*Regards,*
*Palatla Srikanth*

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