Apache Header Buffer Size

proxy_busy_buffers_size: This directive sets the maximum size of buffers that can be marked "client-ready" and thus busy. What is Large Client Header Buffer ? Well for many people in systems engineering, it is probably nothing to be worried about. 1 doesn't appear to set the size of the TCP send buffer. //the position/size of the text field. Three times that size in buffer space is allocated. If not specified, this attribute is set to 2097152 (2 megabytes). The number of subintervals is configured via DataStorageConfiguration. The buffer size should be at least the size of the largest expected header size from a proxied response. The payload starts at packet base location plus all the header lengths. Client Body Buffer Size¶ Sets buffer size for reading client request body per location. In this case, the HTTP Content-Length header cannot be used to delimit the content and the next HTTP request/response, as the content size is not yet known. org) mod_mime can read one byte past the end of a buffer when sending a malicious Content-Type response header. 31 allows remote attackers to cause a denial of service (process crash) and possibly execute arbitrary code via a negative Content-Length HTTP header field, which causes a large amount of data to be copied. MANUAL_FLUSH: the call returns when the operation has been added to the buffer, else it throws a KuduException if the buffer is full. When you determine buffer size settings, you must strike a balance between communication needs and other processing. 1g draft, 4. Index; View on single page; View as JSON; View another version. With proxy_buffering disabled, data received from the server is immediately relayed by nginx, allowing for minimum Time To First Byte (TTFB). Buffer size in bytes used in Zstd compression, in the case when Zstd compression codec is used. # Apache With SSL. Let us now explore a variation of that example. ab will flood the Apache server with requests - as fast as it can generate them (not unlike that of a DDoS attack). parser: A pointer to *parser (needed so calling function can get errors), will be set to NULL on successful completion. The larger the size of the header buffer is, the more memory each open HTTP socket will take. And removing the ETag reduces the size of the HTTP headers in both the response and subsequent requests. (Apache already has mod_proxy module. responseBufferSize: Sets the size of the content buffer for sending responses. To increase Apache's limit for the Request Header Size, add the following line to every WebService_*. Directives to be set/modified are as follows: Below values worked for me, you may like to set it correctly for your needs. The specific flaw is in the apache_request_handlers() function. conf configuration file. Limits the number of HTTP request header fields that will be accepted from the client: LimitRequestFieldSize bytes: 8190 : sv: C: Limits the size of the HTTP request header allowed from the client: LimitRequestLine bytes: 8190 : sv: C: Limit the size of the HTTP request line that will be accepted from the client: LimitXMLRequestBody bytes: 1000000 : svdh: C. This header represents a list of client IP addresses. conf file from. Since they are not installed by default, have your server administrator install them for you. Note: ensure that there are no any other camel-jetty endpoints that share the same port, otherwise this option may not work as expected. c' Remote Buffer Overflow (2). The fragment list and unmapped buffer structures lead to a recursive implementation of checksumming and data movement code that is quite complicated in nature. Not all headers appearing in a response are response headers. Reads a ``PCollection`` of text files or file patterns and and produces a ``PCollection`` of strings. Any problems file an INFRA jira ticket please. DEFAULT_MIN_GZIP_SIZE. Jan 4 23:58:55 local/tmm err tmm[5238]: 011f0005:3: HTTP header (33304) exceeded maximum allowed size of 32768 (Client side: vip=ext_HTTP_VS_80 profile=http pool=Pool_3128) I need advice on inquiry below:. The TCP window scale option is an option to increase the receive window size allowed in Transmission Control Protocol above its former maximum value of 65,535 bytes. While some thread-based servers such as Apache use a timeout when they wait for incomplete HTTP. Consider using ZeroPadding afterwards, to conform to the Arrow layout specification. By Ilya Grigorik on October 24, 2013. I'm assuming this doesn't just mean it's a big page. properties file. While its important to keep a limit for security reasons, it is also important to keep the headers at an acceptable size to increase performance. The length of the size field in a header buffer. If exceeded, parsing will fail using an ArrayOutOfBoundsExceptions. In this case, the HTTP Content-Length header cannot be used to delimit the content and the next HTTP request/response, as the content size is not yet known. Context: http, server, and location. That limit is controlled by the LimitRequestFieldSize directive. We think that with the correct settings of Apache and MySQL you can get excellent results and the correct level of resource use without installing third-party proxy and cache modules. CVE-2012-2329CVE-82215. the first HConstants. Constructs a MultipartIterator with the specified buffer size and the specified file size limit in bytes Parameters: request - The multipart request to iterate bufferSize - The size in bytes that should be read from the input stream at a times maxSize - The maximum size in bytes allowed for a multipart element's data. Message view « Date » · « Thread » Top « Date » · « Thread » From: [email protected] Open and edit file php. BigPipe takes advantage of streaming PHP responses (using flush() to flush the output buffer at various times during a page load), but to ensure the stream is delivered all the way from PHP through to the client, you need to make sure your entire webserver and proxying stack streams the request directly, with no buffering. 5 Attribution License. If the header is already present Knox adds a comma separated value to the list. Checkpointing is used when an end of buffer is reached with an incomplete header, so that the parsing does not start again from the beginning when more data is read. Source code for Apache/mod_wsgi. Any problems file an INFRA jira ticket please. Default value is 43800. Client Body Buffer Size¶ Sets buffer size for reading client request body per location. Sets the size of the buffer for request headers. By default, size is limited by the size of two buffers set by the proxy_buffer_size and proxy_buffers directives. APR_XML_X2T_FULL start tag, contents, end tag APR_XML_X2T_INNER contents only APR_XML_X2T_LANG_INNER xml:lang + inner contents APR_XML_X2T_FULL_NS_LANG FULL + ns defns + xml:lang namespaces The namespace of the current XML element. This document describes JMeter properties. 1 doesn't appear to set the size of the TCP send buffer. hostname The name of the node running the Drillbit service. Depending on the Session's type, we can configure various elements. so が自動的に追加され、RequestHeaderディレクティブが利用可能になります。 あとは、最初に記載した、 RequestHeader unset Range RequestHeader unset Request-Range をhttpd. This is a package header, 7 bytes (FLT2002) public static final byte[] END_DATA : This is the package footer, 7 bytes (TLF2003) protected byte[] buf : Variable to hold the data : protected int: bufSize : Current length of data in the buffer : protected boolean: discard. send-server-version. ServletResponse. Sets the size of the buffer used for reading the first part of the response received from the proxied server. It is required that length be at least the value returned by HdrHeap::marshal_length(). Note that this config file initializes the DefaultParser a CompositeParser, and the CompositeExternalParser, and the MP4Parser. protected int. However, these entity requests are usually called responses. Apache MXNet is an effort undergoing incubation at The Apache Software Foundation (ASF), sponsored by the Apache Incubator. X-Forwarded-Proto. The length of the size field in a header buffer. wire=DEBUG Enables logging the complete wire-level messages received and sent by Synapse. For full documentation of the release, a guide to get started, please refer to Q. Part of this may be due to hardware or network issues, but it could also be because of. You can tweak the response buffer size (response. org>, Jacob Champion, Eric Covener] *) SECURITY: CVE-2017-7679 (cve. Go to Websites & Domains > Apache & nginx Settings. You can set value (in bytes) from 0 (unlimited) to 2147483647 (2GB) that are allowed in a request body. 1 - Session Configuration¶. Third-party libraries may define their own types for special purposes, such as image processing or numeric analysis. properties file. Consider using ZeroPadding afterwards, to conform to the Arrow layout specification. (Note SBT and Scala syntax follows) I've imported. Checkpointing is used when an end of buffer is reached with an incomplete header, so that the parsing does not start again from the beginning when more data is read. LimitRequestBody: Apache Limiting User Upload File Size. (Apache already has mod_proxy module. IBM X-Force: Apache mod_rewrite off-by-one buffer overflow. This patch adds a configurable parameter dfs. This helper routine tests for and reads any message body in the request, simply discarding whatever it receives. setMetricsSubIntervalCount(int) configuration property. When tuning MySQL, the two most important variables to configure are key_buffer_size and table_cache. Let us now explore a variation of that example. SSLRenegBufferSize 10486000 The name and location of the conf file is different depending on distributions. Entries can be instantiated in one of three ways, depending on how they are to be used. Is it possible change. remote exploit for Windows platform. AJP with HTTPD - Buffer Size on long URLs. 1, any method can have a body. Limits the number of HTTP request header fields that will be accepted from the client: LimitRequestFieldSize bytes: 8190 : sv: C: Limits the size of the HTTP request header allowed from the client: LimitRequestLine bytes: 8190 : sv: C: Limit the size of the HTTP request line that will be accepted from the client: LimitXMLRequestBody bytes: 1000000 : svdh: C. Content-Length = "Content-Length" ":" 1*DIGIT An example is Content-Length: 3495. Re: POST Request How to enable Chunk Size scenario is end user speaking in the mobile device the audio stream should be flushed to the speech engine to process as it comes. 7 SSL/TLS Configuration 2. DEFAULT_COMPRESSION. Kafka Streams is a client library for processing and analyzing data stored in Kafka. BasicHeaderValueFormatter. The payload starts at packet base location plus all the header lengths. It usually occurs because of incorrect data and memory handling when the programming subsystem and operating system dont provide. Apache ActiveMQ Artemis supports STOMP 1. The minimum response size to trigger dynamic compression. It builds upon important stream processing concepts such as properly distinguishing between event time and processing time, windowing support, exactly-once processing semantics and simple yet efficient management of application state. WildFly 10 with Apache and AJP Java This article demonstrates how inbound request from a webserver (Apache) can be proxied to an application server (WildFly 10) using the Apache JServ Protocol (AJP). Which client is best? Apache HTTP client has fewer bugs on Eclair and Froyo. The length of time interval is configured via DataStorageConfiguration. Let us now explore a variation of that example. Apache™ FOP¶. Normally, both Nginx and Apache buffer content up to either 4KB The server receives data of 4KB but its buffer size is 8KB so this will not. If the HTTP status code returned by Apache is below 400 the header is correctly set, but if the status is greater or equal 400 the header is omitted. tags | exploit , remote , overflow. With debugging turned on, I can see that my PHP application (SilverStripe) is adding two large headers (X-Include-JS and X-Include-CSS) to the HTTP response of around 3,000 characters each and the first one of these is exceeding a buffer size limit in nginx. This Confluence has been LDAP enabled, if you are an ASF Committer, please use your LDAP Credentials to login. You should also configure your Web server to set cache headers on its HTTP responses. " does buffer reserves memory? or big headers use Processor? What should I pay attention to? memory? CPU power? Please tell me the point to take care. Open and edit file php. client_header_buffer_size: Similar to the previous directive, only instead it handles the client header size. The use of Apache Flume is not only restricted to log data aggregation. Most likely you need to change the SSL buffer size in your apache config file. if om_pkthdr_len is zero, this is a normal mbuf; otherwise it is a packet header mbuf). Buffer size in bytes used in Zstd compression, in the case when Zstd compression codec is used. conf file from. Apache with mod_ssl versions prior to 2. 4 Mitigating Slow HTTP DoS Attack 2. 9 fcgid_header_bucket_read() Function Heap-Based Buffer Overflow. Compute and return the size of the buffer needed to serialize this. Ondrej Kmoch Mar 16, 2015. By default, a buffers of 9000 bytes will be used. 7 OpenSSL - 'OpenFuckV2. In the preceding command, the NetScaler-Client-IP is the header name that is appended to the request. Do not assume that the header line is zero terminated!. LoadModule headers_module modules/mod_headers. Note that it is this field which differentiates packet header mbufs from normal mbufs (i. org: Subject: svn commit: r1823602 - in /tomcat/trunk/java/org/apache/coyote. So to disable output buffering in apache, check if gzip or deflate are enabled and active or not. Size of a request header field exceeds server limit. However if a big cookie is in the request-header or the request has come from a wap-client the header can not be placed in 1K, therefore, the request-header or a line of request-header is not located completely in this buffer nginx allocate a bigger buffer, the size of the bigger buffer can be set with the instruction large_client_header_buffers. PHP Streaming and Output Buffering Explained. 9 HTTP secure Header 2. A third way to to check your HTTP security headers is to scan your website on securityheaders. Most users don't realise that while browsing the WWW there is a constant conversation going on between the browser and the web server. response-buffer-size=nnn. Apache MXNet is an effort undergoing incubation at The Apache Software Foundation (ASF), sponsored by the Apache Incubator. There are currently two release code lines available, versions 0. Returns WAL buffer poll spins number over the last time interval. 2, from "windows. 9 HTTP secure Header 2. In this case, the HTTP Content-Length header cannot be used to delimit the content and the next HTTP request/response, as the content size is not yet known. OSX ships with perl 5. Thanks for all those who purchased and helped in supporting this program. Client Body Buffer Size¶ Sets buffer size for reading client request body per location. STOMP is a text-orientated wire protocol that allows STOMP clients to communicate with STOMP Brokers. Thus securing a data contract (which is type safe) between the two. This TCP option, along with several others, is defined in IETF RFC 1323 which deals with long fat networks (LFNs). 如果你的请求中只有少量请求header很大,那么应该使用large_client_header_buffers,因为这样就仅需在处理大header时才会分配更多的空间,从而减少无谓的内存空间浪费。. For full documentation of the release, a guide to get started, please refer to Q. Multiple Invocations of Filter Handlers. Apache MXNet is an effort undergoing incubation at The Apache Software Foundation (ASF), sponsored by the Apache Incubator. If true, any tag buffer that expands beyond org. Increase REST server header buffer size from 8k to 64k @HBASE-13608 increased rest server http header size to 8k. An example out of our logfile is attached. However, this same ease of flexibility and lack of tuning is typically what leads Apache to becoming a memory hog. Elasticsearch-rest-client-5. BodyContentImpl. Note that this config file initializes the DefaultParser a CompositeParser, and the CompositeExternalParser, and the MP4Parser. In this case, the HTTP Content-Length header cannot be used to delimit the content and the next HTTP request/response, as the content size is not yet known. It would send out this size of data regardless of whether the network thought it wanted less or could take more. It builds upon important stream processing concepts such as properly distinguishing between event time and processing time, windowing support, exactly-once processing semantics and simple yet efficient management of application state. X-Forwarded-Proto. FOO has about 3. AB has no option to set a delay between these requests. OutputStreamOutputBuffer : This class is an output buffer which will write data to an output stream. " does buffer reserves memory? or big headers use Processor? What should I pay attention to? memory? CPU power? Please tell me the point to take care. The LimitRequestFieldSize directive allows the server administrator to reduce or increase the limit on the allowed size of an HTTP request header field. AMQP is an open internet protocol for reliably sending and receiving messages. AJP with HTTPD - Buffer Size on long URLs. This directive sets the size of the buffer for this portion of the response. The nodes and buffers fields are produced by a depth-first traversal / flattening of a schema (possibly containing nested types) for a given in-memory data set. I want to set the value of request-header-buffer-size to 256K. While the HTTP specification does not put a maximum limit on message headers, if more than 24k is needed for HTTP header buffer size, another solution is needed. Sets the size of the buffer for request headers. The payload starts at packet base location plus all the header lengths. It usually occurs because of incorrect data and memory handling when the programming subsystem and operating system dont provide. In the case of the Kafka spout, the max fetch bytes size divided by the average record size defines an effective records per subbatch partition. Communication between apache and wildfly is done by http. It is likely that the read buffer ends with a partial message, this is easily detected by the size delimiting. 1 - Session Configuration¶. Apache Flex® is an Apache project, and is released under the Apache License, version 2. Note that the buffer must be at least big enough to contain the boundary string, plus 4 characters for CR/LF and double dash, plus at least one byte of data. COMPRESSION: Allows using simple compression with the HTTP connector. It is legal for the returned buffer to have zero size, as long as repeatedly calling Next() eventually yields a buffer with non-zero size. The polybase service does not want to start and abruptly shutdown. " does buffer reserves memory? or big headers use Processor? What should I pay attention to? memory? CPU power? Please tell me the point to take care. While the HTTP specification does not put a maximum limit on message headers, if more than 24k is needed for HTTP header buffer size, another solution is needed. The properties present in jmeter. It is important to consider that this queue is held in memory, and setting this size too large could adversely affect the overall memory of the NiFi instance, thus causing problems for the overall flow and not just this processor. Apache mod_jk2 Host Header Multiple Stack Based Buffer Overflow Vulnerabilities Apache mod_jk2 is prone to multiple stack-based buffer-overflow vulnerabilities because it fails to perform adequate boundary checks on user-supplied data before copying it to insufficiently sized buffers. Imagine another file containing some sort of header information that needs to be analyzed before we start appending the file. sendDateHeader. If not specified, the default value of false will be used. remote exploit for Windows platform. TargetHeaders=DEBUG Enables logging the headers of all the HTTP messages exchanged between Synapse and backend servers. Interesting Scenario at a customer for Polybase Service. responseBufferSize: Sets the size of the content buffer for sending responses. 1 doesn't appear to set the size of the TCP send buffer. /* Include the required headers from httpd */ #include "httpd. I had similar issue where I am running apache with ssl configuration. Note: ensure that there are no any other camel-jetty endpoints that share the same port, otherwise this option may not work as expected. txBufSize: The socket send buffer (SO_SNDBUF) size in bytes. c' Remote Buffer Overflow (2). Most web servers have their own set of size limits on HTTP request headers. This patch adds a configurable parameter dfs. To resolve the problem, please check potential size of header sent to server. This tutorial shows how you can set up nginx as a reverse proxy in front of an Apache2 web server on Ubuntu 16. The server header information, such as the name of the server software and version. 8 SSL Module 2. remote exploit for Windows platform. 8 Buffer Overflow APP:MISC:APACHE-QPID-SEQSET-DOS: APP: Apache Qpid Sequence Set Denial of Service APP:MISC:APACHE-QPID-SESS-DOS: APP: Apache Qpid Session Gap Denial of Service APP:MISC:APACHE-SVN-CE: APP: Apache Subversion URL Command Execution APP:MISC:APACHE-SVN-IO. The header size limit can apply to an application when a large amount of data is passed in the request headers. c exploit from 2003. htpasswd which is a text file used by Apache and other applications to store usernames and password for HTTP authentication. HTTP Profile "Maximum Header Size". 1 doesn't appear to set the size of the TCP send buffer. Elasticsearch-rest-client-5. The length of time interval is configured via DataStorageConfiguration. This Apache directive limits the size of the various HTTP header sizes, thereby limiting the chances for a buffer overflow. SequenceFile Header. Configuration Attributes. The TCP transport allows clients to connect to a remote ActiveMQ broker using a TCP socket. Optimize MySQL & Apache on cPanel/WHM server. p: The pool for allocating the parse results. remote exploit for Unix platform. This Confluence has been LDAP enabled, if you are an ASF Committer, please use your LDAP Credentials to login. 2 doc says the max value is 8192, but the 2. Parsing headers is very easy using this. Apache with mod_ssl versions prior to 2. Defines the maximum size that a response header/value can be that is returned from a WSGI application. The default server header is Oracle-iPlanet-Web-Server/7. AbstractHttpEntity protected AbstractHttpEntity() Protected default constructor. The following are the limits of some of the most popular web servers. Optimizing TLS Record Size & Buffering Latency. The size (in bytes) of the buffer used to read HTTP request headers. Configuration Attributes. The number of subintervals is configured via DataStorageConfiguration. Default is GzipHandler. Is there a practical HTTP Header length limit? The longest header line of request also must be not more than the size of one buffer, otherwise the client get the. Interface TarConstants. In Writer headers and footers are considered paragraphs and therefore you can format the header or footer text using the same techniques you use for formatting text in the main body of the document. The following are top voted examples for showing how to use org. I was only successful in producing a working dll by using Visual Studio 6 sp5 with the associated x86 makefile. They need to be large enough to hold text which cannot be > > split, like the names of elements and attributes. The parquet-mr project contains multiple sub-modules, which implement the core components of reading and writing a nested, column-oriented data stream, map this core onto the parquet format, and provide Hadoop Input/Output Formats, Pig loaders, and other Java-based utilities for interacting with Parquet. And even then, nginx still has to allocate the required proxy_buffer_size chunk of memory for reading HTTP headers returned by upstream server. server-header. [Yann Ylavic] *) Fix HttpProtocolOptions to inherit from global to VirtualHost scope. It is a very busy environment (> 25 million hits a day) so it'll take me some time to pick through. How to enable ETag in Apache Http Server If your using Apache HTTP Server then you can use it to generate and return ETag for static resources that are served from disk. The LimitRequestFieldSize directive allows the server administrator to reduce or increase the limit on the allowed size of an HTTP request header field. datIDSVia64. An idle connection at most has one buffer of this size allocated. TarEntries that are created from the header bytes read from an archive are instantiated with the TarEntry(byte[]) constructor. Apache mod_jk2 Host Header Multiple Stack Based Buffer Overflow Vulnerabilities Apache mod_jk2 is prone to multiple stack-based buffer-overflow vulnerabilities because it fails to perform adequate boundary checks on user-supplied data before copying it to insufficiently sized buffers. go to bug id or search bugs for : apache_response_headers() does not include duplicate headers Size of PHP file affects behaviour of virtual() or #include. 3 - apache_request_headers Function Buffer Overflow (Metasploit). The Apache HTTP Server modules mod_imap and mod_imagemap are vulnerable to cross-site scripting. SequenceFile. Content-Length = "Content-Length" ":" 1*DIGIT An example is Content-Length: 3495. conf, WebService_101. Http11Protocol. In IIS, Apache and Tomcat the default value of client header size is big enough to cause this evil wake up from its dream state. htpasswd which is a text file used by Apache and other applications to store usernames and password for HTTP authentication. Note: When using Apache, make sure you have the libapache2-mod-php package installed or else PHP will not display on your webserver. Contribute to GrahamDumpleton/mod_wsgi development by creating an account on GitHub. The contentType, contentEncoding and chunked attributes of the created object are set to null, null and false, respectively. I had similar issue where I am running apache with ssl configuration. For Apache, mod_expires and mod_headers handle cache control through HTTP headers sent from the server. I'm using add_header X-Content-Type-Options nosniff; in nginx to add this header to every response. 3 doc says the minimum is 512 with no mention of a maximum. In the meantime, the rest of the buffers can be used for reading the response and, if needed, buffering part of the response to a temporary file. parser: A pointer to *parser (needed so calling function can get errors), will be set to NULL on successful completion. In this code, 32 bytes of storage are assigned to memory location buffer via the malloc() function at Line 12. This header represents a list of client IP addresses. But according to Help, "Allowing large headers might hit the server's performance. Provides workarounds. The length of time interval is configured via DataStorageConfiguration. txBufSize: The socket send buffer (SO_SNDBUF) size in bytes. I'll try and investigate the actual URL. We saw http header size exceeding 7k with. Request Floods. Proxy Auth roles header x_auth_token: Proxy Auth token header x_auth_username: Proxy Auth username header couch_peruser: couch_peruser: couch_peruser Options delete_dbs enable couchdb: couchdb: Base CouchDB Options attachment_stream_buffer_size: Attachment streaming buffer database_dir. properties file. However, the automatic tuning might not occur fast enough for consumers that need to start “hot. When a chunk size is 0, the receiver knows all the data has been received. Default is 6K. (It does so to work around a bug in a popular browser. The limit can be disabled by setting this attribute to a value less than or equal to 0. The number of subintervals is configured via DataStorageConfiguration. wire=DEBUG Enables logging the complete wire-level messages received and sent by Synapse. Apache™ FOP¶. The protocol used in the client request. Size a custom Buffer Tank, generate a submittal, and send a quote request in just seconds! We’ve also made it easy to convert compression tanks into bladder expansion tanks. FileETag INode MTime Size to. If memory is scarce, consider 1 MB. 0 Final behind it. Hello, First message, so this is bound to be extremely dumb mistake, it certainly feels that. This would give a good performance for small documents (less than 10K). This module exploits a buffer overflow in PHP. By default, a buffers of 9000 bytes will be used. More information here. The Web Server is a crucial part of web-based applications. 6 Tuning HTTP Request and Response Limits. 1, and Apache Hadoop 2. The new buffer size also affects the maximum length for gzprintf(). Under certain circumstances, content generators might create content in small chunks. Incubation is required of all newly accepted projects until a further review indicates that the infrastructure, communications, and decision making process have stabilized in a manner consistent with other successful ASF. I am attempt to buffer a query parameter and set the value in an environment variable to overwrite the X-Forwarded-For header, but with out success. Buffer size in bytes used in Zstd compression, in the case when Zstd compression codec is used. # time of this writing. TraceEnable Directive. The fastcgi_buffers setting takes two values, buffer segment count and memory size, by default it will be: fastcgi_buffers 8 4k|8k; So a total of 8 buffer segments at either 4k/8k, which is determined by the platform memory page size. When enabled, WebHDFS HTTP requests to the NameNode or DataNode must include a custom HTTP header. For Gingerbread and better, HttpURLConnection is the best choice. How to enable ETag in Apache Http Server If your using Apache HTTP Server then you can use it to generate and return ETag for static resources that are served from disk. This is 8K on x86, other 32-bit platforms, and x86-64. In the meantime, the rest of the buffers can be used for reading the response and, if needed, buffering part of the response to a temporary file.