Проблема балансировки нагрузки apache mod_jk для экземпляров кластера Glassfish

У меня есть приложение JEE ear, развернутое на 2 кластерах по 2 экземпляра на Glassfish v3.1. Они сбалансированы по нагрузке сервером Apache, работающим на той же машине. Моя проблема в том, что я часто вижу следующие сообщения об ошибках в файле mod_jk.log. Можете ли вы помочь мне понять, в чем проблема?

[Mon Jun 13 09:37:51 2011] [7116:7852] [info] ajp_process_callback::jk_ajp_common.c (1885): Writing to client aborted or client network problems

[Mon Jun 13 09:37:51 2011] [7116:7852] [info] ajp_service::jk_ajp_common.c (2543): (viewerLocalInstance4) sending request to tomcat failed (unrecoverable), because of client write error (attempt=1)

[Mon Jun 13 09:37:51 2011] loadbalancerLocal myServer 0.062500

[Mon Jun 13 09:37:51 2011] [7116:6512] [info] ajp_process_callback::jk_ajp_common.c (1885): Writing to client aborted or client network problems

[Mon Jun 13 09:37:51 2011] [7116:6512] [info] ajp_service::jk_ajp_common.c (2543): (viewerLocalInstance4) sending request to tomcat failed (unrecoverable), because of client write error (attempt=1)

[Mon Jun 13 09:37:52 2011] [7116:3080] [info] ajp_process_callback::jk_ajp_common.c (1885): Writing to client aborted or client network problems

[Mon Jun 13 09:37:52 2011] [7116:3080] [info] ajp_service::jk_ajp_common.c (2543): (viewerLocalInstance4) sending request to tomcat failed (unrecoverable), because of client write error (attempt=1)

[Mon Jun 13 09:38:21 2011] [7116:6512] [info] service::jk_lb_worker.c (1388): service failed, worker viewerLocalInstance4 is in local error state

[Mon Jun 13 09:38:21 2011] [7116:7852] [info] service::jk_lb_worker.c (1388): service failed, worker viewerLocalInstance4 is in local error state

[Mon Jun 13 09:38:21 2011] [7116:6512] [info] service::jk_lb_worker.c (1407): unrecoverable error 200, request failed. Client failed in the middle of request, we can't recover to another instance.

[Mon Jun 13 09:38:21 2011] [7116:7852] [info] service::jk_lb_worker.c (1407): unrecoverable error 200, request failed. Client failed in the middle of request, we can't recover to another instance.

[Mon Jun 13 09:38:21 2011] loadbalancerLocal myServer 29.046875

[Mon Jun 13 09:38:21 2011] loadbalancerLocal myServer 29.171875

[Mon Jun 13 09:38:21 2011] [7116:6512] [info] jk_handler::mod_jk.c (2620): Aborting connection for worker=loadbalancerLocal

[Mon Jun 13 09:38:21 2011] [7116:7852] [info] jk_handler::mod_jk.c (2620): Aborting connection for worker=loadbalancerLocal

[Mon Jun 13 09:38:21 2011] [7116:7852] [info] ajp_process_callback::jk_ajp_common.c (1885): Writing to client aborted or client network problems

[Mon Jun 13 09:38:21 2011] [7116:7852] [info] ajp_service::jk_ajp_common.c (2543): (viewerLocalInstance4) sending request to tomcat failed (unrecoverable), because of client write error (attempt=1)

[Mon Jun 13 09:38:21 2011] loadbalancerLocal myServer 0.156250

[Mon Jun 13 09:38:21 2011] loadbalancerLocal myServer 0.062500

[Mon Jun 13 09:38:22 2011] [7116:3080] [info] service::jk_lb_worker.c (1388): service failed, worker viewerLocalInstance4 is in local error state

[Mon Jun 13 09:38:22 2011] [7116:3080] [info] service::jk_lb_worker.c (1407): unrecoverable error 200, request failed. Client failed in the middle of request, we can't recover to another instance.