Table of Contents for
Squid: The Definitive Guide
Squid: The Definitive Guide
Published by
O'Reilly Media, Inc., 2004
- Cover
- Squid: The Definitive Guide
- Squid: The Definitive Guide
- Dedication
- Preface
- 1. Introduction
- 2. Getting Squid
- 3. Compiling and Installing
- 4. Configuration Guide for the Eager
- 5. Running Squid
- 6. All About Access Controls
- 7. Disk Cache Basics
- 8. Advanced Disk Cache Topics
- 9. Interception Caching
- 10. Talking to Other Squids
- 11. Redirectors
- 12. Authentication Helpers
- 13. Log Files
- 14. Monitoring Squid
- 15. Server Accelerator Mode
- 16. Debugging and Troubleshooting
- A. Config File Reference
- http_port
- https_port
- ssl_unclean_shutdown
- icp_port
- htcp_port
- mcast_groups
- udp_incoming_address
- udp_outgoing_address
- cache_peer
- cache_peer_domain
- neighbor_type_domain
- icp_query_timeout
- maximum_icp_query_timeout
- mcast_icp_query_timeout
- dead_peer_timeout
- hierarchy_stoplist
- no_cache
- cache_access_log
- cache_log
- cache_store_log
- cache_swap_log
- emulate_httpd_log
- log_ip_on_direct
- cache_dir
- cache_mem
- cache_swap_low
- cache_swap_high
- maximum_object_size
- minimum_object_size
- maximum_object_size_in_memory
- cache_replacement_policy
- memory_replacement_policy
- store_dir_select_algorithm
- mime_table
- ipcache_size
- ipcache_low
- ipcache_high
- fqdncache_size
- log_mime_hdrs
- useragent_log
- referer_log
- pid_filename
- debug_options
- log_fqdn
- client_netmask
- ftp_user
- ftp_list_width
- ftp_passive
- ftp_sanitycheck
- cache_dns_program
- dns_children
- dns_retransmit_interval
- dns_timeout
- dns_defnames
- dns_nameservers
- hosts_file
- diskd_program
- unlinkd_program
- pinger_program
- redirect_program
- redirect_children
- redirect_rewrites_host_header
- redirector_access
- redirector_bypass
- auth_param
- authenticate_ttl
- authenticate_cache_garbage_interval
- authenticate_ip_ttl
- external_acl_type
- wais_relay_host
- wais_relay_port
- request_header_max_size
- request_body_max_size
- refresh_pattern
- quick_abort_min
- quick_abort_max
- quick_abort_pct
- negative_ttl
- positive_dns_ttl
- negative_dns_ttl
- range_offset_limit
- connect_timeout
- peer_connect_timeout
- read_timeout
- request_timeout
- persistent_request_timeout
- client_lifetime
- half_closed_clients
- pconn_timeout
- ident_timeout
- shutdown_lifetime
- acl
- http_access
- http_reply_access
- icp_access
- miss_access
- cache_peer_access
- ident_lookup_access
- tcp_outgoing_tos
- tcp_outgoing_address
- reply_body_max_size
- cache_mgr
- cache_effective_user
- cache_effective_group
- visible_hostname
- unique_hostname
- hostname_aliases
- announce_period
- announce_host
- announce_file
- announce_port
- httpd_accel_host
- httpd_accel_port
- httpd_accel_single_host
- httpd_accel_with_proxy
- httpd_accel_uses_host_header
- dns_testnames
- logfile_rotate
- append_domain
- tcp_recv_bufsize
- err_html_text
- deny_info
- memory_pools
- memory_pools_limit
- forwarded_for
- log_icp_queries
- icp_hit_stale
- minimum_direct_hops
- minimum_direct_rtt
- cachemgr_passwd
- store_avg_object_size
- store_objects_per_bucket
- client_db
- netdb_low
- netdb_high
- netdb_ping_period
- query_icmp
- test_reachability
- buffered_logs
- reload_into_ims
- always_direct
- never_direct
- header_access
- header_replace
- icon_directory
- error_directory
- maximum_single_addr_tries
- snmp_port
- snmp_access
- snmp_incoming_address
- snmp_outgoing_address
- as_whois_server
- wccp_router
- wccp_version
- wccp_incoming_address
- wccp_outgoing_address
- delay_pools
- delay_class
- delay_access
- delay_parameters
- delay_initial_bucket_level
- incoming_icp_average
- incoming_http_average
- incoming_dns_average
- min_icp_poll_cnt
- min_dns_poll_cnt
- min_http_poll_cnt
- max_open_disk_fds
- offline_mode
- uri_whitespace
- broken_posts
- mcast_miss_addr
- mcast_miss_ttl
- mcast_miss_port
- mcast_miss_encode_key
- nonhierarchical_direct
- prefer_direct
- strip_query_terms
- coredump_dir
- ignore_unknown_nameservers
- digest_generation
- digest_bits_per_entry
- digest_rebuild_period
- digest_rewrite_period
- digest_swapout_chunk_size
- digest_rebuild_chunk_percentage
- chroot
- client_persistent_connections
- server_persistent_connections
- pipeline_prefetch
- extension_methods
- request_entities
- high_response_time_warning
- high_page_fault_warning
- high_memory_warning
- ie_refresh
- vary_ignore_expire
- sleep_after_fork
- B. The Memory Cache
- C. Delay Pools
- D. Filesystem Performance Benchmarks
- E. Squid on Windows
- F. Configuring Squid Clients
- About the Author
- Colophon
- Copyright
Name
query_icmp
Synopsis
Enabling this directive instructs Squid to ask its neighbors for their ICMP measurements, which are included in ICP/HTCP replies. This, essentially, populates your netdb database with your neighbors’ ICMP measurements. The bulk “netdb exchange” is another way to receive those measurements (see Section 10.5).
Squid uses the neighbors’ netdb
measurements when making forwarding decisions. If one of the parents
is closer to the origin server, Squid forwards the request there and
marks it with CLOSEST_PARENT_MISS
in access.log.