Can not read response from server. Expected to read 4 bytes...
Hi, we are receiving the following intermittent CF error a lot recently and wondering if you could help diagnose this issue... Message: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost. Detail: Communications link failure The last packet successfully received from the server was 256,215 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago. This always seems to occur on a query that queries multiple tables in multiple database - specifically it is collecting user email addresses from 73 databases on our server. Our hosting provider has stated this seems to be a CF error and advised us to uncheck the 'Maintain connection' options for each datasource. They recommended this on the basis of reading the following post: http://www.cjboco.com/blog.cfm/post/coldfusion-error/ Before I try this I wanted to double check this was in fact the right advice and whether this would cause any additional problems? Thanks for your advice Richard ~| Order the Adobe Coldfusion Anthology now! http://www.amazon.com/Adobe-Coldfusion-Anthology/dp/1430272155/?tag=houseoffusion Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:355649 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/groups/cf-talk/unsubscribe.cfm
Re: Can not read response from server. Expected to read 4 bytes...
we are receiving the following intermittent CF error a lot recently and wondering if you could help diagnose this issue... Message: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost. Detail: Communications link failure The last packet successfully received from the server was 256,215 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago. This always seems to occur on a query that queries multiple tables in multiple database - specifically it is collecting user email addresses from 73 databases on our server. Our hosting provider has stated this seems to be a CF error and advised us to uncheck the 'Maintain connection' options for each datasource. They recommended this on the basis of reading the following post: http://www.cjboco.com/blog.cfm/post/coldfusion-error/ Before I try this I wanted to double check this was in fact the right advice and whether this would cause any additional problems? I'm unclear on what you're actually doing. You're running a single query that's querying 73 separate databases? If so, that seems like the problem you need to fix, rather than disabling the maintain connections option in your CF data sources. Disabling JDBC connection pooling will usually significantly degrade performance. If you're unable to change or fix that query, I'd recommend creating a separate CF data source that you use just to run that query, and disabling maintain connections for just that one data source. Dave Watts, CTO, Fig Leaf Software http://www.figleaf.com/ http://training.figleaf.com/ Fig Leaf Software is a Veteran-Owned Small Business (VOSB) on GSA Schedule, and provides the highest caliber vendor-authorized instruction at our training centers, online, or onsite. ~| Order the Adobe Coldfusion Anthology now! http://www.amazon.com/Adobe-Coldfusion-Anthology/dp/1430272155/?tag=houseoffusion Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:355650 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/groups/cf-talk/unsubscribe.cfm
Re: Can not read response from server. Expected to read 4 bytes...
Thanks Dave, good idea. Ill setup the separate database for this query. Yes unfortunately this query specifically collects data from all databases. I used to have it as a single query per database inside of a loop but this caused an error signifying too many connections. The query is as follows: cfquery name=userExistsInDatasource datasource=rebasedb_manage cfloop index=i from=1 to=#getAllDatasources.recordcount# !--- ENSURE ALL THE SELECT STATEMENTS GET ADDED TOGETHER --- cfif i gt 1 UNION /cfif SELECT #getAllDatasources.datasourceid[i]# as datasourceid, userid FROM rebasedb_#getAllDatasources.datasourceid[i]#.users !--- add the where clause which applies the filters entered into the grid --- WHERE email = cfqueryparam value=#session.currentUser.email# cfsqltype=cf_sql_varchar maxlength=50 /cfloop /cfquery we are receiving the following intermittent CF error a lot recently and wondering if you could help diagnose this issue... Message: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost. Detail: Communications link failure The last packet successfully received from the server was 256,215 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago. This always seems to occur on a query that queries multiple tables in multiple database - specifically it is collecting user email addresses from 73 databases on our server. Our hosting provider has stated this seems to be a CF error and advised us to uncheck the 'Maintain connection' options for each datasource. They recommended this on the basis of reading the following post: http://www.cjboco.com/blog.cfm/post/coldfusion-error/ Before I try this I wanted to double check this was in fact the right advice and whether this would cause any additional problems? I'm unclear on what you're actually doing. You're running a single query that's querying 73 separate databases? If so, that seems like the problem you need to fix, rather than disabling the maintain connections option in your CF data sources. Disabling JDBC connection pooling will usually significantly degrade performance. If you're unable to change or fix that query, I'd recommend creating a separate CF data source that you use just to run that query, and disabling maintain connections for just that one data source. Dave Watts, CTO, Fig Leaf Software http://www.figleaf.com/ http://training.figleaf.com/ Fig Leaf Software is a Veteran-Owned Small Business (VOSB) on GSA Schedule, and provides the highest caliber vendor-authorized instruction at our training centers, online, or onsite. ~| Order the Adobe Coldfusion Anthology now! http://www.amazon.com/Adobe-Coldfusion-Anthology/dp/1430272155/?tag=houseoffusion Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:355651 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/groups/cf-talk/unsubscribe.cfm
Re: Can not read response from server. Expected to read 4 bytes...
I would suggest some data warehouse techniques here. Where you would extract the emails from 73 databases and insert them all into one database and table and run the query against that single table. Doing a 73 table union is just never going to work well even with proper indexing. Byron Mann Lead Engineer Architect HostMySite.com On May 5, 2013 4:09 PM, Richard White rich...@re-base.net wrote: Thanks Dave, good idea. Ill setup the separate database for this query. Yes unfortunately this query specifically collects data from all databases. I used to have it as a single query per database inside of a loop but this caused an error signifying too many connections. The query is as follows: cfquery name=userExistsInDatasource datasource=rebasedb_manage cfloop index=i from=1 to=#getAllDatasources.recordcount# !--- ENSURE ALL THE SELECT STATEMENTS GET ADDED TOGETHER --- cfif i gt 1 UNION /cfif SELECT #getAllDatasources.datasourceid[i]# as datasourceid, userid FROM rebasedb_#getAllDatasources.datasourceid[i]#.users !--- add the where clause which applies the filters entered into the grid --- WHERE email = cfqueryparam value=#session.currentUser.email# cfsqltype=cf_sql_varchar maxlength=50 /cfloop /cfquery ~| Order the Adobe Coldfusion Anthology now! http://www.amazon.com/Adobe-Coldfusion-Anthology/dp/1430272155/?tag=houseoffusion Archive: http://www.houseoffusion.com/groups/cf-talk/message.cfm/messageid:355652 Subscription: http://www.houseoffusion.com/groups/cf-talk/subscribe.cfm Unsubscribe: http://www.houseoffusion.com/groups/cf-talk/unsubscribe.cfm
