http://git-wip-us.apache.org/repos/asf/geode-native/blob/ff80a931/geode-docs/reference/topics/glossary.html.md.erb ---------------------------------------------------------------------- diff --git a/geode-docs/reference/topics/glossary.html.md.erb b/geode-docs/reference/topics/glossary.html.md.erb deleted file mode 100644 index f039066..0000000 --- a/geode-docs/reference/topics/glossary.html.md.erb +++ /dev/null @@ -1,601 +0,0 @@ ---- -title: Glossary ---- - -This glossary defines terms used in Apache Geode documentation. - -## <a id="glossary__section_DAFADE21D316465481B71C795FF77AD5" class="no-quick-link"></a>ACK wait threshold - -A time-to-wait for message acknowledgment between system members. - -## <a id="glossary__section_C3F8A17C6458419AAE109F6E4719FFB1" class="no-quick-link"></a>administrative event - -See [event](glossary.html#glossary__section_2AF9B98BC1CA402A9F24E552EE9C9ACF). - -## <a id="glossary__section_E54C1FFAF4644954B54FA78A4EE5FC44" class="no-quick-link"></a>API - -Application Programming Interface. Geode provides APIs to cached data for Java applications. - -## <a id="glossary__section_1DCB29DBB9064E82A4CC0A6413191820" class="no-quick-link"></a>application program - -A program designed to perform a specific function directly for the user or, in some cases, for another application program. Geode applications use the Geode application programming interfaces (APIs) to modify cached data. - -## <a id="glossary__section_1E6C71FF293148BE853D0C7D657F90ED" class="no-quick-link"></a>attribute - -Querying: A named member of a data object. The public fields and methods of an object may be accessed as attributes in the context of a query. - -Region: See [region attributes](glossary.html#glossary__section_7398A81EE9034E7FBDF7B592314586B3). - -## <a id="glossary__section_8B77F26807044FAD96134DEB21AD0590" class="no-quick-link"></a>attribute path - -A sequence of attributes separated by a dot (.), applied to objects where the value of each attribute is used to apply the next attribute. - -## <a id="glossary__section_D86690A5E9B444CE969AB6D92BC25127" class="no-quick-link"></a>blocking - -A behavior associated with synchronization functions. Blocking behavior is exhibited as waiting for a signal to proceed, regardless of how long it takes. See also [timeout](glossary.html#glossary__section_311C7AE4126A4B1899D6EA1C4E804F57). - -## <a id="glossary__section_938DF854708546878D59694A4C68604C" class="no-quick-link"></a>cache - -In-memory Geode data storage created by an application or cache server for data storage, distribution, and management. This is the point of access for Java applications for all caching features, and the only view of the cache that is available to the application. Cache creation creates a connection to the distributed system. See also [local](glossary.html#glossary__section_598D82A75D9842438BB934E01E77266E) and [remote](glossary.html#glossary__section_CC864725C0014791805D2549D87DA545). - -## <a id="glossary__section_F63DF98EB5D04EB5BBF9C6AD923341F5" class="no-quick-link"></a>cache-local - -Residing or occurring in the local cache. - -## <a id="glossary__section_3527F588E0B844F783D4A98E248F0E4B" class="no-quick-link"></a>cache.xml - -Common name for the XML file that declares the initial configuration of a cache. This file is used to customize the behavior of the Geode cache server process and can be used by any Java application. Applications can also configure the cache through the Geode Java APIs. You can give this file any name. - -## <a id="glossary__section_61C824936B6E495D9214EE7E0F0C0F63" class="no-quick-link"></a>cache event - -See [event](glossary.html#glossary__section_2AF9B98BC1CA402A9F24E552EE9C9ACF). - -## <a id="glossary__section_688E118C48B246AF9D2AAB64AE9481D4" class="no-quick-link"></a>cache listener - -User-implemented plug-in for receiving and handling region entry events. A regionâs cache listener is called after an entry in the local cache is modified. See also [cache writer](glossary.html#glossary__section_40FFA1BD5E4A4E3084AE8B257C612EDE). - -## <a id="glossary__section_9CAA8CD20DBF4F948E20E384C987D0C8" class="no-quick-link"></a>cache loader - -User-implemented plug-in for loading data into a region. A regionâs cache loader is used to load data that is requested of the region but is not available in the distributed system. For a distributed region, the loader that is used can be in a different cache from the one where the data-request operation originated. See also [netSearch](glossary.html#glossary__section_B9B118509831405D9AB4069503119DFB) and [netLoad](glossary.html#glossary__section_BFFF4BF9D6414AA392F7AEAC1256C112).cache misses, where a requested key is not present or has a null value in the local cache. - -## <a id="glossary__section_6D9FA50812AC45BCADA7755E4368A5C4" class="no-quick-link"></a>cache miss - -The situation where a keyâs value is requested from a cache and the requested key is not present or has a null value. Geode responds to cache misses in various ways, depending on the region and system configuration. For example, a client region goes to its servers to satisfy cache misses. A region with local scope uses its data loader to load the value from an outside data source, if a loader is installed on the region. - -## <a id="glossary__section_cache_server" class="no-quick-link"></a>cache server - -A long-lived, configurable Geode distributed system member process that can service client connections. - -## <a id="glossary__section_cache_transaction" class="no-quick-link"></a>cache transaction - -A native Geode transaction, managed by Geode and not by JTA. This type of transaction operates only on data available from the Geode cache in the local member. See also [JTA](glossary.html#glossary__section_2B4ADA311CA946839F3E8F3B071D4E74) and [global transaction](glossary.html#glossary__section_CDA3C2530A74433CBE0204D588C237AC). - -## <a id="glossary__section_40FFA1BD5E4A4E3084AE8B257C612EDE" class="no-quick-link"></a>cache writer - -User-implemented plug-in intended for synchronizing the cache with an outside data source. A regionâs cache writer is a synchronous listener to cache data events. The cache writer has the ability to abort a data modification. See also [cache listener](glossary.html#glossary__section_688E118C48B246AF9D2AAB64AE9481D4) and [netWrite](glossary.html#glossary__section_3B75FF1066664923B2C9A61BDA133559). - -## <a id="glossary__section_109B7961FDFC4EED8C1802E84031B38D" class="no-quick-link"></a>client - -A Geode application that is configured as a standalone distributed system member, with regions configured as client regions. Client configuration uses the <client-cache> `cache.xml` element and the ClientCache API. - -## <a id="glossary__section_A586ED6889724255957630F01B2E54F4" class="no-quick-link"></a>client region - -A Geode cache region that is configured to go to one or more Geode servers, in a separate Geode distributed system, for all data distribution activities. Among other things, client regions go to servers to satisfy cache misses, distribute data modifications, and to run single queries and continuous queries. - -## cluster configuration service - -The cluster configuration service saves cluster configurations created by gfsh commands to the locators in a cluster and distributes the configurations to members of the cluster. - -## <a id="glossary__section_054DE9007EFB49119CE9B4725DCA6C14" class="no-quick-link"></a>collection - -Used in the context of a query for a group of distinct objects of homogeneous type, referred to as elements. Valid collections include the `java.util.Collection` as well as Set, Map, List, and arrays. The elements in a collection can be iterated over. Iteration over a Map traverses its entries as instances of Map.Entry. A region can also be treated as a collection of its values. - -## <a id="glossary__section_F8C00E335E9C4F1EA717F717B2A0E7FE" class="no-quick-link"></a>commit - -A transactional operation that merges a transactionâs result into the cache. Changes are made in an "all or none" fashion. Other changes from outside the current transaction are kept separate from those being committed. - -## <a id="glossary__section_3699AD8BD21249178882247DF7C12104" class="no-quick-link"></a>concurrency-level - -Region attribute that specifies an estimate of the number of threads ever expected to concurrently modify values in the region. The actual concurrency may vary; this value is used to optimize the allocation of system resources. - -## <a id="glossary__section_3FEC7A097CE247299F47EA209C5F91B8" class="no-quick-link"></a>conflation - -Combining entries in a message queue for better performance. When an event is added to queue, if a similar event exists in the queue, there are two ways to conflate the events. One way is to remove the existing entry from wherever it resides in the queue, and add the new entry to the end of the queue. The other way is to replace the existing entry with the new entry, where it resides in the queue, and add nothing to the end of the queue. In Geode, region entry update events, server events going to clients, and gateway sender events going to remote distributed systems can all be conflated. - -## <a id="glossary__section_6D18D4A3D0D046E6B3664B4C95065EB3" class="no-quick-link"></a>connection - -The connection used by an application to access a Geode system. A Java application connects to its Geode distributed system when it creates its cache. The application must connect to a distributed system to gain access to the Geode functionalities. A client connects to a running Geode server to distribute data and events between itself and the server tier. These client connections are managed by server connection pools within the client applications. Gateway senders connect to a remote gateway receiver to distribute data events between sites. - -## <a id="glossary__section_32D2C413690A4F44BA8F7B0F2AF3CD1A" class="no-quick-link"></a>consumer - -Geode member process that receives data and/or events from other members. Peer consumers are often configured with replicated regions, so all changes in the distributed system arrive into the local cache. Client consumers can register subscriptions with their servers so that updates are automatically forwarded from the server tier. See [producer](glossary.html#glossary__section_8742E7E064364DED98D4D399B98DBCF3). - -## <a id="glossary__section_E02DBBD928D54E8C82EC59B5CCC528EF" class="no-quick-link"></a>coordinator - -The member of the distributed system that sends out membership views. This is typically the locator in Geode. - -## <a id="glossary__section_6049C4E876C24615B245D8E2A92E3D89" class="no-quick-link"></a>data accessor - -In the context of a region, a member configured to use a region, but not store any data for it in the memberâs local cache. Common use cases for data accessors are thin clients, and thin producer and consumer applications. Accessors can put data into the region and receive events for the region from remote members or servers, but they store no data in the application. See also [data store](glossary.html#glossary__section_CC99958C53D84AD38E15E3BEDEA5F61D). - -## <a id="glossary__section_A8EE060D11E645D3B3FCDE0E5181F163" class="no-quick-link"></a>data entry - -See [entry](glossary.html#glossary__section_5D8ED880C9BD4062BE6F0404B28FA005). - -## <a id="glossary__section_6D48D75AAC28486697EA3A5E66AEEF04" class="no-quick-link"></a>data fabric - -Also referred to as an in-memory data grid or an enterprise data fabric. Geode is an implementation of a data fabric. A data fabric is a distributed, memory-based data management platform that uses cluster-wide resources -- memory, CPU, network bandwidth, and optionally local disk -- to manage application data and application logic (behavior). The data fabric uses dynamic replication and data partitioning techniques to offer continuous availability, very high performance, and linear scalability for data intensive applications, all without compromising on data consistency even when exposed to failure conditions. - -## <a id="glossary__section_41C4996366BF4CD4BF290E6DF6E2F20D" class="no-quick-link"></a>data-policy - -Region attribute used to determine what events the region receives from remote caches, whether data is stored in the local cache, and whether the data is persisted to disk. For disk persistence, writes are performed according to the cache disk-store configuration. - -## <a id="glossary__section_348DF8B2F8984813897E1BCEB2CEDD59" class="no-quick-link"></a>data region (region) - -A logical grouping of data within a cache. Regions usually contain data entries (see entry). Each region has a set of region attributes governing activities such as expiration, distribution, data loading, events, and capacity control. In addition, a region can have an application-defined user attribute. - -## <a id="glossary__section_CC99958C53D84AD38E15E3BEDEA5F61D" class="no-quick-link"></a>data store - -In the context of a region, a member configured to store data for the region. This is used mostly for partitioned regions, where data is spread across the distributed system among the data stores. See also [data accessor](glossary.html#glossary__section_6049C4E876C24615B245D8E2A92E3D89). - -## <a id="glossary__section_53D31D86FA12426E8412A2F45BBAE34A" class="no-quick-link"></a>deadlock - -A situation in which two or more processes are waiting indefinitely for events that will never occur. - -## <a id="glossary__section_179D08FF635F4A939F59C44914254410" class="no-quick-link"></a>destroy - -Distributed: To remove a cached object across the distributed cache. - -Local: To remove a cached object from the local cache only. - -## <a id="glossary__section_C2B05EDE9FDB478AB99C8DCD290A91B3" class="no-quick-link"></a>disk region - -A persistent region. - -## <a id="glossary__section_672E5F70BE09465589253DEA25FA90EA" class="no-quick-link"></a>disk-store - -Cache element specifying location and write behavior for disk storage. Used for persistence and overflow of data. The cache can have multiple disk stores, which are specified by name for region attributes, client subscription queues (for servers), and WAN gateway sender queues. - -## <a id="glossary__section_1BE6131144994E89A8F68685D8DCF490" class="no-quick-link"></a>distributed cache - -A collection of caches spread across multiple machines and multiple locations that functions as a single cache for the individual applications. - -## <a id="glossary__section_94901F2666594813BAE6761DF4CEF0ED" class="no-quick-link"></a>distributed system - -One or more Geode system members that have been configured to communicate cache events with each other, forming a single, logical system. - -## <a id="glossary__section_FC39A1F63F4D40FC9B3DF00F1A75282E" class="no-quick-link"></a>distributed-ack scope - -Data distribution setting that causes synchronous distribution operations, which wait for acknowledgment from other caches before continuing. Operations from multiple caches can arrive out of order. This scope is slower but more reliable than distributed-no-ack. - -## <a id="glossary__section_35D0344DB4684FD69EFC01F599F2F349" class="no-quick-link"></a>distributed-no-ack-scope - -Data distribution setting that causes asynchronous distribution operations, which return without waiting for a response from other caches. This scope produces the best performance, but is prone to race conditions. - -## <a id="glossary__section_5D8ED880C9BD4062BE6F0404B28FA005" class="no-quick-link"></a>entry - -A data object in a region consisting of a key and a value. The value is either null (invalid) or a Java object. A region entry knows what region it is in. An entry can have an application-defined user attribute. See also [region data](glossary.html#glossary__section_CDA009928A3041F2AEE914F7BD3590C7), [entry key](glossary.html#glossary__section_1B630E274E6B45D2850A405276A39307), and [entry value](glossary.html#glossary__section_C79B084B7945436C89518D64E75E1D8E). - -## <a id="glossary__section_1B630E274E6B45D2850A405276A39307" class="no-quick-link"></a>entry key - -The unique identifier for an entry in a region. - -## <a id="glossary__section_C79B084B7945436C89518D64E75E1D8E" class="no-quick-link"></a>entry value - -The data contained in an entry. - -## <a id="glossary__section_2AF9B98BC1CA402A9F24E552EE9C9ACF" class="no-quick-link"></a>event - -An action recognized by the Geode system members, which can respond by executing callback methods. The Geode API produces two types of events: cache events for detail-level management of applications with data caches and administrative events for higher-level management of the distributed system and its components. An operation can produce administrative events, cache events, or both. - -## <a id="glossary__section_1B57CC3632B843AA89CB321489C3B91C" class="no-quick-link"></a>eviction-attributes - -Region attribute that causes the cache to limit the size of the region by removing old entries to make space for new ones. - -## <a id="glossary__section_FA56C0CD24254B18B6B428BAD00F45D0" class="no-quick-link"></a>expiration - -A cached object expires when its time-to-live or idle timeout counters are exhausted. A region has one set of expiration attributes for itself and one set for all of its entries. - -## <a id="glossary__section_5ADAA5E628FB421999C286D38A2AA1DD" class="no-quick-link"></a>expiration action - -The action to be taken when a cached object expires. The expiration action specifies whether the object is to be invalidated or destroyed and whether the action is to be performed only in the local cache or throughout the distributed system. A destroyed object is completely removed from the cache. A region is invalidated by invalidating all entries contained in the region. An entry is invalidated by having its value marked as invalid. Region.getEntry.getValue returns null for an invalid entry. - -In Geode, expiration attributes are set at the region level for the region and at the entry level for entries. See also idle timeout and time-to-live. - -## <a id="glossary__section_5CFFD2274BAD4A73849B3AA854BA4661" class="no-quick-link"></a>factory method - -An interface for creating an object which at creation time can let its subclasses decide which class to instantiate. The factory method helps instantiate the appropriate subclass by creating the correct object from a group of related classes. - -## <a id="glossary__section_87AAD34154CB49C4A47B88FFDAAFE690" class="no-quick-link"></a>forced disconnect - -Forcible removal of a member from membership without the memberâs consent. - -## <a id="glossary__section_A4B70DE75E364C4796B1ADA75A09E935" class="no-quick-link"></a>gateway receiver - -A gateway receiver defines connection information for receiving region events that were distributed from a gateway sender in a multi-site deployment. - -## <a id="glossary__section_1AAED2CD15094B2FBE7B6064176884CD" class="no-quick-link"></a>gateway sender - -A gateway sender defines a single remote distributed system site and an associated queue for distributing region events in a multi-site deployment. - -## <a id="glossary__section_B7B1440197B84F72B1145A44032768C4" class="no-quick-link"></a>gemfire.properties - -Common name for the file used for distributed system configuration, including system member connection and communication behavior, logging and statistics files and settings, and security settings. Applications can also configure the distributed system through the Geode Java APIs. You can give this file any name. - -## <a id="glossary__section_6838A6C252464E94965F05E285A94689" class="no-quick-link"></a>global scope - -Data distribution setting that provides locking across the distributed system for load, create, put, invalidate, and destroy operations on the region and its entries. This scope is the slowest, but it guarantees consistency across the distributed system. - -## <a id="glossary__section_CDA3C2530A74433CBE0204D588C237AC" class="no-quick-link"></a>global transaction - -A JTA-controlled transaction in which multiple resources, such as the Geode cache and a JDBC database connection, participate. JTA coordinates the completion of the transaction with each of the transactionâs resources. See also [JTA](glossary.html#glossary__section_2B4ADA311CA946839F3E8F3B071D4E74) and [cache transaction](glossary.html#glossary__section_cache_transaction). - -## <a id="glossary__section_46D4C19244A3481290BF5C54E4DFE951" class="no-quick-link"></a>HTTP - -World Wide Webâs Hypertext Transfer Protocol. A standard protocol used to request and transmit information over the Internet or other computer network. - -## <a id="glossary__section_F47AA14129D547A1902ABB187FB2C5C6" class="no-quick-link"></a>idle timeout - -The amount of time a region or region entry may remain in the cache without being accessed before being expired. Access to an entry includes any get operation and any operation that resets the entryâs time-to-live counter. Region access includes any operation that resets an entry idle timeout and any operation that resets the regionâs time-to-live. - -Idle timeout attributes are set at the region level for the region and at the entry level for entries. See also [time-to-live](glossary.html#glossary__section_5FAE668DDCBE4DAAA8484D1AF7B56BA1) and [expiration action](glossary.html#glossary__section_5ADAA5E628FB421999C286D38A2AA1DD). - -## <a id="glossary__section_63AEBDFB0E8D40F997CEB0AA8FCEF9D9" class="no-quick-link"></a>initial capacity - -Region attribute. The initial capacity of the map used for storing region entries. - -## <a id="glossary__section_BF6876F505F041BFB659CEBB90FD3EB0" class="no-quick-link"></a>invalid - -The state of an object when the cache holding it does not have the current value of the object. - -## <a id="glossary__section_D495B444E5CF4BDFB47BEA591717D6F5" class="no-quick-link"></a>invalidate - -Distributed: To mark an object as being invalid across the distributed cache. - -Local: To mark an object as being invalid in the local cache only. - -## <a id="glossary__section_CD699284896148BA9FEB9E5FC0219473" class="no-quick-link"></a>JDBC - -Java DataBase Connectivity. A programming interface that lets Java applications access a database via the SQL language. - -## <a id="glossary__section_32730D08B6BA4C02A3FE8F164449437E" class="no-quick-link"></a>JMX - -Java Management eXtensions. A set of specifications for dynamic application and network management in the J2EE development and application environment. - -## <a id="glossary__section_979B07C140C2480CAC56D7AE3D0F1402" class="no-quick-link"></a>JNDI - -Java Naming and Directory Interface. An interface to naming and directory services for Java applications. Applications can use JNDI to locate data sources, such as databases to use in global transactions. Geode allows its JNDI to be configured in a `cache.xml` configuration file. - -## <a id="glossary__section_2B4ADA311CA946839F3E8F3B071D4E74" class="no-quick-link"></a>JTA - -Java Transaction API. The local Java interfaces between a transaction manager (JTS) and the parties involved in a global transaction. Geode can be a member of a JTA global transaction. See also [global transaction](glossary.html#glossary__section_CDA3C2530A74433CBE0204D588C237AC). - -## <a id="glossary__section_731F788890994955863C24BF1FED7F56" class="no-quick-link"></a>JVM - -Java Virtual Machine. A virtual machine capable of handling Java bytecode. - -## <a id="glossary__section_28D0F94F67CA4976A837210B21941A42" class="no-quick-link"></a>key constraint - -Enforcing a specific entry key type. The key-constraint region attribute, when set, constrains the entries in the region to keys of the specified object type. - -## <a id="glossary__section_62EFBE99B8FD4B0FBF4C766973720318" class="no-quick-link"></a>listener - -An event handler. The listener registers its interest in one or more events, such as region entry updates, and is notified when the events occur. - -## <a id="glossary__section_FEC5A706B30741AF9305678DD840846E" class="no-quick-link"></a>load factor - -Region attribute. The load factor of the map used for storing entries. - -## <a id="glossary__section_598D82A75D9842438BB934E01E77266E" class="no-quick-link"></a>local - -Local cache: The part of the distributed cache that is resident in the current memberâs memory. This term is used to differentiate the cache where a specific operation is being performed from other caches in the same distributed system or in another distributed system. See also [remote](glossary.html#glossary__section_CC864725C0014791805D2549D87DA545). - -Region with local scope: A region whose scope is set to local. This type of region does not distribute anything with other members in the distributed system. - -Region shortcuts: In the RegionShortcut and settings, LOCAL means the scope is set to local. All client regions have local scope. In the ClientRegionShortcut settings, LOCAL means the region does not connect to the clientâs servers. - -## <a id="glossary__section_6EF84234B9A4453299A218BE10DA516F" class="no-quick-link"></a>local scope - -Data distribution setting that keeps data private and visible only to threads running within the local member. A region with local scope is completely contained in the local cache. Client regions are automatically given local scope. - -## <a id="glossary__section_32B3520764624A87976126603BC8AFE6" class="no-quick-link"></a>locator - -Geode process that tracks system members and provides current membership information to joining members so they can establish communication. For server systems, the locator also tracks servers and server load and, when a client requests a server connection, the locator sends the client to one of the least loaded servers. . - -## <a id="glossary__section_AED421A3C46349168730605059F9B2B0" class="no-quick-link"></a>LRU - -Least recently used. Used to refer to region entry or entries most eligible for eviction due to lack of interest by client applications. Geode offers eviction controllers that use the LRU status of a regionâs entries to determine which to evict to free up space. Possible eviction actions are local destroy and overflow. See also [resource manager](glossary.html#glossary__section_A8EA732962854C499CA06CAD40084AA2). - -## <a id="glossary__section_ACCE0EBD75C64DEA9563ECA18802E3EC" class="no-quick-link"></a>machine - -Any Geode-supported physical machine or Virtual Machine. - -## <a id="glossary__section_51E160ED7FEF40469FD3D6BA80792393" class="no-quick-link"></a>member - -A process that has defined a connection to a Geode distributed system and created a Geode cache. This can be a Java or Native Client application. This can also be a Geode process such as a locator or cacheserver. The minimal Geode process configuration is a single member that is connected to a distributed system. - -## <a id="glossary__section_B43A3D6E64AF487480B32B78567C06E7" class="no-quick-link"></a>message queue - -A first-in, first-out data structure in a Geode system member that stores messages for distribution in the same order that the original operations happened in the local member. Each thread has its own queue. Depending on the kind of queue, the messages could be going between two members of a distributed system, a client and server, or two members in different distributed systems. See also [conflation](glossary.html#glossary__section_3FEC7A097CE247299F47EA209C5F91B8). - -## <a id="glossary__section_012843121ADE4BB883151BA8C8425C6C" class="no-quick-link"></a>mirroring - -See [replicate](glossary.html#glossary__section_9B9E43530AD3486BB1B5EB035B0CED73). - -## <a id="glossary__section_66112989304F4BE6B48C47B0BB535724" class="no-quick-link"></a>multicast - -A form of UDP communications where a datagram is sent to multiple processes in one network operation. - -## <a id="glossary__section_3C8EB8194A494BF2978CC0495C3B3443" class="no-quick-link"></a>named region attributes - -Region attributes that are stored in the member memory and can be retrieved through their region attributes refid setting. Geode provides standard predefined named region attributes, that are stored using region shortcut refids. You can use any stored attributes that you wish, setting an id when you create them and using the id setting in the refid you want to use to retrieve them. - -## <a id="glossary__section_BFFF4BF9D6414AA392F7AEAC1256C112" class="no-quick-link"></a>netLoad - -The method used by Geode to load an entry value into a distributed region. The netLoad operation invokes all remote cache loaders defined for the region until either the entry value is successfully loaded or all loaders have been tried. - -## <a id="glossary__section_B9B118509831405D9AB4069503119DFB" class="no-quick-link"></a>netSearch - -The method used by Geode to search remote caches for a data entry that is not found in the memberâs local cache region. This method operates only on distributed regions with a data-policy of empty, normal and preloaded. - -## <a id="glossary__section_3B75FF1066664923B2C9A61BDA133559" class="no-quick-link"></a>netWrite - -The method used by Geode to invoke a cache writer for region and region entry events. This method operates only on distributed regions. For each event, if any cache writer is defined for the region, the netWrite operation invokes exactly one of them. - -## <a id="glossary__section_ECBDD95CCC6445B2ADDFC8F4010BD459" class="no-quick-link"></a>network partitioning - -A situation that arises from a communications partition that causes processes to become unaware of one another. - -## <a id="glossary__section_481A0A6447C94013B53A0C662D6A0EF4" class="no-quick-link"></a>OQL - -Object Query Language, SQL-92 extended for querying object data. Geode supports a subset of OQL. - -## off-heap memory - -Memory that is not on the standard Java heap and that is not managed by the JVM and its garbage collector. - -## <a id="glossary__section_7280947960B243108B9C0764EE5BB678" class="no-quick-link"></a>overflow - -Eviction option for eviction controllers. This causes the values of LRU entries to be moved to disk when the region reaches capacity. Writes are performed according to the cache disk-store configuration. - -## <a id="glossary__section_F583E7A1E181482190E73CE03A205090" class="no-quick-link"></a>oplog / operation log - -The files in a disk-store used for the cache operations. - -## <a id="glossary__section_A8F0CD8F7EA94FBC8BF954A8A8EEC8E5" class="no-quick-link"></a>partition - -The memory in each member that is reserved for a specific partitioned regionâs use. - -## <a id="glossary__section_297905699D6A47C1BF456651582C2D69" class="no-quick-link"></a>partitioned region - -A region that manages large volumes of data by partitioning it into manageable chunks and distributing it across multiple machines. Defining partition attributes or setting the region attribute data-policy to partition makes the region a partitioned region. - -## <a id="glossary__section_B291531710DE4C0FA9D98263C6756AAB" class="no-quick-link"></a>peer - -A Geode member application that is not configured as a client. Peer configuration uses the <cache> `cache.xml` element and the Cache API. Peers can also be configured as servers to client applications and as gateway-receivers or gateway-senders to remote distributed systems. - -## <a id="glossary__section_244F67CD366141858D3B3771E3E58889" class="no-quick-link"></a>persistent region - -A region with the attribute data-policy set to persistent-replicate. - -## <a id="glossary__section_9B0A50A73A5A4B02A18E9557BF73A6B9" class="no-quick-link"></a>persistent-partition - -A region attribute setting identifying a region as a partitioned region whose data is persisted to disk. With persistence, all region entry keys and values are stored in an operation log on disk as well as being stored in memory. Also referred to as disk region. Writes are performed according to the cache disk-store configuration. - -## <a id="glossary__section_A600283F2A314BB5A06E2FBE55BD74EE" class="no-quick-link"></a>persistent-replicate - -A region attribute setting identifying a region as a replicate whose data is persisted to disk. With persistence, all region entry keys and values are stored in an operation log on disk as well as being stored in memory. Also referred to as disk region. Writes are performed according to the cache disk-store configuration. - -## <a id="glossary__section_8742E7E064364DED98D4D399B98DBCF3" class="no-quick-link"></a>producer - -A Geode member process that puts data into the cache for consumption by other members. Producers may be configured with empty regions, where the data they put into the cache is not stored locally, but causes cache update events to be sent to other members. This is a common configuration in peer members and for client processes. See [consumer](glossary.html#glossary__section_32D2C413690A4F44BA8F7B0F2AF3CD1A). - -## <a id="glossary__section_900E459B58914FBFB20480F722F4F46E" class="no-quick-link"></a>pull model - -Data distribution model where each process receives updates only for the data in which the process has explicitly expressed interest. In a Geode peer member, this is accomplished using a distributed, non-replicated region and creating the data entries that are of interest in the local region. When updates happen for the region in remote caches, the only updates that are forwarded to the local cache are those for entries that are already defined in the local cache. In a Geode client, you get pull behavior by specifically subscribing to the entries of interest. See [push model](glossary.html#glossary__section_B8D00D2F5F574FB4B8D082FA62384D9F). - -## <a id="glossary__section_B8D00D2F5F574FB4B8D082FA62384D9F" class="no-quick-link"></a>push model - -Data distribution model where each process receives updates for everything in the data set. In a Geode peer member, this is accomplished using a replicated region. All data modifications, creations, and deletes in remote caches are pushed to the replicated region. In a Geode client, you get push behavior by registering interest in all keys in the region. See [pull model](glossary.html#glossary__section_900E459B58914FBFB20480F722F4F46E). - -## <a id="glossary__section_1C769F32BEFD4760B325D7B0730E878C" class="no-quick-link"></a>query string - -A fully-formed SQL statement that can be passed to a query engine and executed against a data set. A query string may or may not contain a SELECT statement. - -## <a id="glossary__section_6F3899F6F9CB41668471CFB931D33F4B" class="no-quick-link"></a>race condition - -Anomalous behavior caused by the unexpected dependence on the relative timing of events. Race conditions often result from incorrect assumptions about possible ordering of events. - -## <a id="glossary__section_E21653B0F7CD4E7E9C51731EB0362228" class="no-quick-link"></a>range-index - -An XPath index optimized for range-queries with the added index maintenance expense of sorting the set of values. A range index allows faster retrieval of the set of nodes with values in a certain range. See also [structure-index](glossary.html#glossary__section_78C4D8B8C40E4A5688F2426A3F46A234) and [value-index](glossary.html#glossary__section_927F5452A1C840B9BFA119693CA5B26F). - -## <a id="glossary__section_601C6D4BA8384E8EB245421BDEE1CBDF" class="no-quick-link"></a>region - -A logical grouping of data within a cache. Regions usually contain data entries (see [entry](glossary.html#glossary__section_5D8ED880C9BD4062BE6F0404B28FA005)). Each region has a set of region attributes governing activities such as expiration, distribution, data loading, events, and capacity control. In addition, a region can have an application-defined user attribute. - -## <a id="glossary__section_7398A81EE9034E7FBDF7B592314586B3" class="no-quick-link"></a>region attributes - -The class of attributes governing the creation, distribution, and management of a region and its entries. - -## <a id="glossary__section_CDA009928A3041F2AEE914F7BD3590C7" class="no-quick-link"></a>region data - -All of the entries directly contained in the region. - -## <a id="glossary__section_35F856172C7A4FD89BA3873750B41605" class="no-quick-link"></a>region entry - -See [entry](glossary.html#glossary__section_5D8ED880C9BD4062BE6F0404B28FA005). - -## <a id="glossary__section_982788E772C540368610D43AF4AF6046" class="no-quick-link"></a>region shortcut - -Enums RegionShortcut and ClientRegionShortcut defining the main region types in Geode for peers/servers and clients, respectively. Region shortcuts are predefined named region attributes. - -## <a id="glossary__section_CC864725C0014791805D2549D87DA545" class="no-quick-link"></a>remote - -Resident or running in a cache other than the current memberâs cache, but connected to the current memberâs cache through Geode. For example, if a member does not have a data entry in the region in its local cache, it can do a netSearch in an attempt to retrieve the entry from the region in a remote cache within the same distributed system. Or, if the member is a client, it can send a request to a server in an attempt to retrieve the entry from the region in a remote server cache in the serverâs distributed system. In multi-site installations, a gateway sends events from the local cache to remote caches in other distributed systems. See also [local](glossary.html#glossary__section_598D82A75D9842438BB934E01E77266E). - -## <a id="glossary__section_90D41320BD05471D81382209A4D5F4D8" class="no-quick-link"></a>replicated region - -A region with data-policy set to replicate or persistent-replicate. - -## <a id="glossary__section_9B9E43530AD3486BB1B5EB035B0CED73" class="no-quick-link"></a>replicate - -Region data-policy specification indicating to copy all distributed region data into the local cache at region creation time and to keep the local cache consistent with the distributed region data. - -## <a id="glossary__section_A8EA732962854C499CA06CAD40084AA2" class="no-quick-link"></a>resource manager - -Geode process that works with your JVMâs tenured garbage collection (GC) to control heap use and protect your JVM from hangs and crashes due to memory overload. The manager prevents the cache from consuming too much memory by evicting old data and, if the collector is unable to keep up, by refusing additions to the cache until the collector has freed an adequate amount of memory. Eviction is done for regions configured for LRU eviction based on heap percentage. See also [LRU](glossary.html#glossary__section_AED421A3C46349168730605059F9B2B0) and [eviction-attributes](glossary.html#glossary__section_1B57CC3632B843AA89CB321489C3B91C). - -## <a id="glossary__section_82276B0AED4543518C98E173C1528735" class="no-quick-link"></a>rollback - -A transactional operation that excludes a transactionâs changes from the cache, leaving the cache undisturbed. - -## <a id="glossary__section_4EFDFCCA6AA84AEB9B96E3D0345AD910" class="no-quick-link"></a>scope - -Region attribute: In non-partitioned regions, a distribution property for data identifying whether it is distributed and, if so, whether distribution acknowledgements are required and whether distributed synchronization is required. A distributed regionâs cache loader and cache writer (defined in the local cache) can be invoked for operations originating in remote caches. A region that is not distributed has a local scope. See also [replicate](glossary.html#glossary__section_9B9E43530AD3486BB1B5EB035B0CED73). - -Querying: The data context for the part of the query currently under evaluation. The expressions in a SELECT statementâs FROM clause can add to the data that is in scope in the query. - -## <a id="glossary__section_C9C6FDAD0D7846F5BC794C7D29E2524A" class="no-quick-link"></a>SELECT statement - -A statement of the form SELECT projection\_list FROM expressions WHERE expressions that can be passed to the query engine, parsed, and executed against data in the local cache. - -## <a id="glossary__section_68A1E3D86A8D4FD0834A5030C36840D4" class="no-quick-link"></a>serialization - -The process of converting an object or object graph to a stream of bytes. - -## <a id="glossary__section_24A690A7422E460EB61D3B95795A89F0" class="no-quick-link"></a>server - -A Geode member application that is configured as a peer in its own system and as a server to connecting Geode client applications. - -## <a id="glossary__section_3A6AB71E3D844134AB8B51D676F84AEE" class="no-quick-link"></a>server group - -An optional logical grouping of servers in a server distributed system. There is always the default server group made up of all available server in the server distributed system. Clients can specify the server group in their server pool configuration. Then the pool only connects to those servers. If no group is specified, the default is used. - -## <a id="glossary__section_C344F00B5D234CD8A44DD8814ACBD165" class="no-quick-link"></a>server connection pool - -The cache entity that manages client connections to servers. - -## <a id="glossary__section_344B1F6D6E79455788D593600732AD6F" class="no-quick-link"></a>socket - -The application interface for TCP/IP communications. UDP provides unicast and multicast datagram sockets, while TCP provides server and connection sockets. TCP server sockets are used by server processes to create connection sockets between the server and a client. - -## <a id="glossary__section_CE71B3F4A6374257B88A357736DAE07A" class="no-quick-link"></a>SQL - -Structured Query Language. - -## <a id="glossary__section_7CBAA2DDAA9E45B99537BE3638E3B3DB" class="no-quick-link"></a>SSL - -Secure Socket Layer. A protocol for secure communication between Java VMs. - -## <a id="glossary__section_D7E92873D90C4D698E812BA9DCB85392" class="no-quick-link"></a>standalone distributed system - -A distributed system configured for no communication with peers. Client applications are generally defined with standalone distributed systems, so there is no peer communication and all event and data communication is done between the client member and the server tier. - -## <a id="glossary__section_6215C25884CB4E68BECEEED11E7F7FA1" class="no-quick-link"></a>statistics enabled - -Region attribute. Specifies whether to collect statistics for the region. - -## <a id="glossary__section_78D2AEF29750400E9F3703B5ABFD6AED" class="no-quick-link"></a>struct - -A data type that has a fixed number of elements, each of which has a field name and can contain an object value. - -## <a id="glossary__section_78C4D8B8C40E4A5688F2426A3F46A234" class="no-quick-link"></a>structure-index - -An XPath index that is basically a pre-computed query. Any legal XPath expression can be used. The index maintains lists of all nodes that match the expression used to create it. If a query is performed that has the same expression as the index then the result is available without XPath evaluation. See also [range-index](glossary.html#glossary__section_E21653B0F7CD4E7E9C51731EB0362228) and [value-index](glossary.html#glossary__section_927F5452A1C840B9BFA119693CA5B26F). - -## <a id="glossary__section_DAE92AE0BD1F44188F419A1DE7FBF671" class="no-quick-link"></a>system member - -See [member](glossary.html#glossary__section_ACCE0EBD75C64DEA9563ECA18802E3EC). - -## <a id="glossary__section_574E58CDEB9D4E93B0F042883A780B74" class="no-quick-link"></a>TCP - -The Transmission Control Protocol is a part of the internet protocol (IP) suite that provides unicast communications with guaranteed delivery. The TCP protocol is connection-based, meaning that a TCP socket can only be used to send messages between one pair of processes at a time. Compare to [UDP](glossary.html#glossary__section_DB1CE436E9A4430E8B0E8C8AFE13D780). - -## <a id="glossary__section_311C7AE4126A4B1899D6EA1C4E804F57" class="no-quick-link"></a>timeout - -A behavior associated with synchronization functions. Timeout behavior is exhibited as refusal to wait longer than a specified time for a signal to proceed. See also [blocking](glossary.html#glossary__section_D86690A5E9B444CE969AB6D92BC25127). - -## <a id="glossary__section_5FAE668DDCBE4DAAA8484D1AF7B56BA1" class="no-quick-link"></a>time-to-live - -The amount of time a region or region entry may remain in the cache without being modified before being expired. Entry modification includes creation, update, and removal. Region modification includes creation, update, or removal of the region or of any of its entries. - -Time-to-live attributes are set at the region level for the region and at the entry level for entries. See also [idle timeout](glossary.html#glossary__section_F47AA14129D547A1902ABB187FB2C5C6) and [expiration action](glossary.html#glossary__section_5ADAA5E628FB421999C286D38A2AA1DD). - -## <a id="glossary__section_14E906988DCF4ED4970F042C6FF4270E" class="no-quick-link"></a>transaction - -See [cache transaction](glossary.html#glossary__section_cache_transaction) and [global transaction](glossary.html#glossary__section_CDA3C2530A74433CBE0204D588C237AC). - -## <a id="glossary__section_E61321FA86384399AD7A8A7CF0D890AD" class="no-quick-link"></a>transaction listener - -User-implemented plug-in for receiving and handling transaction events. A transaction listener is called after a transaction commits. See also [transaction writer](glossary.html#glossary__section_2D8954C87A83480799694F72CC82D206). - -## <a id="glossary__section_2D8954C87A83480799694F72CC82D206" class="no-quick-link"></a>transaction writer - -User-implemented plug-in intended for synchronizing the cache with an outside data source. A transaction writer is a synchronous listener to cache transactions. The transaction writer has the ability to veto a transaction. See also [transaction listener](glossary.html#glossary__section_E61321FA86384399AD7A8A7CF0D890AD). - -## <a id="glossary__section_ABDC26632C2D46B5B7AE726AD23DB278" class="no-quick-link"></a>transactional view - -The result of a history of transactional operations for a given open transaction. - -## <a id="glossary__section_975C7D9AC377453B96F2DEC3B341C644" class="no-quick-link"></a>transport layer - -The network used to connect the Geode system members in a Geode system. - -## <a id="glossary__section_94B886825B1640269017386D5731A086" class="no-quick-link"></a>TTL - -See [time-to-live](glossary.html#glossary__section_5FAE668DDCBE4DAAA8484D1AF7B56BA1). - -## <a id="glossary__section_DB1CE436E9A4430E8B0E8C8AFE13D780" class="no-quick-link"></a>UDP - -The User Datagram Protocol is a part of the internet protocol (IP) suite that provides simple, unreliable transmission of datagram messages from one process to another. Reliability must be implemented by applications using UDP. The UDP protocol is connectionless, meaning that the same UDP socket can be used to send or receive messages to or from more than one process. Compare to [TCP](glossary.html#glossary__section_574E58CDEB9D4E93B0F042883A780B74). - -## <a id="glossary__section_9EF1D3F165554BF2BA8C4A8BFC2AA9E1" class="no-quick-link"></a>unicast - -A message sent from one process to another process (point-to-point communications). Both UDP and TCP provide unicast messaging. - -## <a id="glossary__section_FB9A30181A9A481594848CABA28EE1FC" class="no-quick-link"></a>URI - -Uniform Resource Identifier. A unique identifier for abstract or physical resources on the World Wide Web. - -## <a id="glossary__section_6D2DED48DC5D464CA4959668C3BA38D5" class="no-quick-link"></a>user attribute - -An optional object associated with a region or a data entry where an application can store data about the region or entry. The data is accessed by the application only. Geode does not use these attributes. Compare to region attributes, which are used by Geode. - -## <a id="glossary__section_8386E2FB49424CA4B5F0343F9E6A04E5" class="no-quick-link"></a>value constraint - -Enforcing a specific entry value type. The value-constraint region attribute, when set, constrains the entries in the region to values of the specified object type. Value constraints can be used to provide object typing for region querying and indexing. The value-constraint is only checked in the cache that does the entry put or create operation. When the entry is distributed to other caches, the value constraint is not checked. - -## <a id="glossary__section_927F5452A1C840B9BFA119693CA5B26F" class="no-quick-link"></a>value-index - -An XPath index that operates much as a structure-index does, but that separates the nodes that match the XPath expression into sets mapped by each nodeâs value. This allows further filtering of the nodes to be evaluated in a query by going directly to those with a specific value. See also [structure-index](glossary.html#glossary__section_78C4D8B8C40E4A5688F2426A3F46A234) and [range-index](glossary.html#glossary__section_E21653B0F7CD4E7E9C51731EB0362228). - -## <a id="glossary__section_01EEADCCE78645829342A441E7524857" class="no-quick-link"></a>view - -A collection of member identifiers that defines the membership group. - -## <a id="glossary__section_E49E2FFF34FC4B2A9E3FF1FF77DCE5DF" class="no-quick-link"></a>Virtual Machine - -A completely isolated operating system installation within your normal operating system. This is generally implemented by software emulation or hardware virtualization. - -## <a id="glossary__section_754A470EEE424D42A9981D068936631B" class="no-quick-link"></a>VMware virtual machine - -Also referred to as a VMware VM. A VMware VM is a tightly isolated software container that can run its own operating systems and applications as if it were a physical computer. A VMware VM behaves exactly like a physical computer and contains it own virtual (ie, software-based) CPU, RAM hard disk and network interface card (NIC). An operating system can't tell the difference between a VMware VM and a physical machine, nor can applications or other computers on a network. Even the VMware VM thinks it is a "real" computer. Nevertheless, a VMware VM is composed entirely of software and contains no hardware components whatsoever. - -## <a id="glossary__section_B7758E29850D459DA197C0FDF25508E1" class="no-quick-link"></a>XML - -EXtensible Markup Language. An open standard for describing data, XML is a markup language similar to HTML. Both are designed to describe and transform data, but where HTML uses predefined tags, XML allows tags to be defined inside the XML document itself. Thus, virtually any data item can be identified. The XML programmer creates and implements data-appropriate tags whose syntax is defined in a DTD file or an XSD (XML schema definition.) - -## <a id="glossary__section_B65D71221D6F4F02B829EE4DB12FFCAB" class="no-quick-link"></a>XML schema definition - -The definition of the structure, content, and semantics used in an XML document. The definition can be used to verify that each item of content in a document adheres to the specification of the element in which the content is placed. The XML schema is a superset of DTD. Unlike DTD, XML schemas are written in XML syntax, which, although more verbose than DTD, are more descriptive and can have stronger typing. Files containing XML schema definitions generally have the XSD extension. - -## <a id="glossary__section_36183B68888F4C49B5E5F36D16C12710" class="no-quick-link"></a>XPath - -A language that describes a way to locate and process items in Extensible Markup Language (XML) documents by using an addressing syntax based on a path through the document's logical structure or hierarchy. - -## XSD - -See XML schema definition. - -
http://git-wip-us.apache.org/repos/asf/geode-native/blob/ff80a931/geode-docs/reference/topics/handling_exceptions_and_failures.html.md.erb ---------------------------------------------------------------------- diff --git a/geode-docs/reference/topics/handling_exceptions_and_failures.html.md.erb b/geode-docs/reference/topics/handling_exceptions_and_failures.html.md.erb deleted file mode 100644 index 0fd854c..0000000 --- a/geode-docs/reference/topics/handling_exceptions_and_failures.html.md.erb +++ /dev/null @@ -1,15 +0,0 @@ ---- -title: Exceptions and System Failures ---- - -Your application needs to catch certain classes to handle all the exceptions and system failures thrown by Apache Geode. - -- `GemFireCheckedException`. This class is the abstract superclass of exceptions that are thrown and declared. Wherever possible, GemFire exceptions are checked exceptions. `GemFireCheckedException` is a Geode version of `java.lang.Exception`. -- `GemFireException`. This class is the abstract superclass of unchecked exceptions that are thrown to indicate conditions for which the developer should not normally need to check. You can look at the subclasses of `GemFireException` to see all the runtime exceptions in the GemFire system; see the class hierarchy in the online Java API documentation. `GemFireException` is a Geode version of java.lang.`RuntimeException`. You can also look at the method details in the `Region` API javadocs for Geode exceptions you may want to catch. -- `SystemFailure`. In addition to exception management, Geode provides a class to help you manage catastrophic failure in your distributed system, particularly in your application. The Javadocs for this class provide extensive guidance for managing failures in your system and your application. See `SystemFailure` in the `org.apache.geode` package. - -To see the exceptions thrown by a specific method, refer to the method's online Java documentation. - -A Geode system member can also throw exceptions generated by third-party software such as JGroups or `java.lang` classes. For assistance in handling these exceptions, see the vendor documentation. - - http://git-wip-us.apache.org/repos/asf/geode-native/blob/ff80a931/geode-docs/reference/topics/memory_requirements_for_cache_data.html.md.erb ---------------------------------------------------------------------- diff --git a/geode-docs/reference/topics/memory_requirements_for_cache_data.html.md.erb b/geode-docs/reference/topics/memory_requirements_for_cache_data.html.md.erb deleted file mode 100644 index 2de6d98..0000000 --- a/geode-docs/reference/topics/memory_requirements_for_cache_data.html.md.erb +++ /dev/null @@ -1,31 +0,0 @@ ---- -title: Memory Requirements for Cached Data ---- - -Geode solutions architects need to estimate resource requirements for meeting application performance, scalability and availability goals. - -These requirements include estimates for the following resources: - -- memory -- number of machines -- network bandwidth - -The information here is only a guideline, and assumes a basic understanding of Geode. While no two applications or use cases are exactly alike, the information here should be a solid starting point, based on real-world experience. Much like with physical database design, ultimately the right configuration and physical topology for deployment is based on the performance requirements, application data access characteristics, and resource constraints (i.e., memory, CPU, and network bandwidth) of the operating environment. - -- **[Core Guidelines for Geode Data Region Design](../../reference/topics/memory_requirements_guidelines_and_calc.html#topic_ipt_dqz_j4)** - -- **[Memory Usage Overview](../../reference/topics/memory_requirements_guidelines_and_calc.html#topic_ppn_pqz_j4)** - -- **[Calculating Application Object Overhead](../../reference/topics/memory_requirements_guidelines_and_calc.html#topic_kjx_brz_j4)** - -- **[Using Key Storage Optimization](../../reference/topics/memory_requirements_guidelines_and_calc.html#topic_exn_2tz_j4)** - -- **[Measuring Cache Overhead](../../reference/topics/memory_requirements_guidelines_and_calc.html#topic_ac4_mtz_j4)** - -- **[Estimating Management and Monitoring Overhead](../../reference/topics/memory_requirements_guidelines_and_calc.html#topic_i1m_stz_j4)** - -- **[Determining Object Serialization Overhead](../../reference/topics/memory_requirements_guidelines_and_calc.html#topic_psn_5tz_j4)** - -- **[Calculating Socket Memory Requirements](../../reference/topics/memory_requirements_guidelines_and_calc.html#topic_d3g_c5z_j4)** - - http://git-wip-us.apache.org/repos/asf/geode-native/blob/ff80a931/geode-docs/reference/topics/memory_requirements_guidelines_and_calc.html.md.erb ---------------------------------------------------------------------- diff --git a/geode-docs/reference/topics/memory_requirements_guidelines_and_calc.html.md.erb b/geode-docs/reference/topics/memory_requirements_guidelines_and_calc.html.md.erb deleted file mode 100644 index 82c93e6..0000000 --- a/geode-docs/reference/topics/memory_requirements_guidelines_and_calc.html.md.erb +++ /dev/null @@ -1,269 +0,0 @@ -<a id="topic_ipt_dqz_j4"></a> - -# Core Guidelines for Geode Data Region Design - -The following guidelines apply to region design: - -- For 32-bit JVMs: If you have a small data set (< 2GB) and a read-heavy requirement, you should be using replicated regions. -- For 64-bit JVMs: If you have a data set that is larger than 50-60% of the JVM heap space you can use replicated regions. For read heavy applications this can be a performance win. For write heavy applications you should use partitioned caches. -- If you have a large data set and you are concerned about scalability you should be using partitioned regions. -- If you have a large data set and can tolerate an on-disk subset of data, you should be using either replicated regions or partitioned regions with overflow to disk. -- If you have different data sets that meet the above conditions, then you might want to consider a hybrid solution mixing replicated and partition regions. Do not exceed 50 to 75% of the JVM heap size depending on how write intensive your application is. - -## <a id="topic_ppn_pqz_j4" class="no-quick-link"></a>Memory Usage Overview - -The following guidelines should provide a rough estimate of the amount of memory consumed by your system. - -Memory calculation about keys and entries (objects) and region overhead for them can be divided by the number of members of the distributed system for data placed in partitioned regions only. For other regions, the calculation is for each member that hosts the region. Memory used by sockets, threads, and the small amount of application overhead for Geode is per member. - -For each entry added to a region, the Geode cache API consumes a certain amount of memory to store and manage the data. This overhead is required even when an entry is overflowed or persisted to disk. Thus objects on disk take up some JVM memory, even when they are paged to disk. The Java cache overhead introduced by a region, using a 32-bit JVM, can be approximated as listed below. - -Actual memory use varies based on a number of factors, including the JVM you are using and the platform you are running on. For 64-bit JVMs, the usage will usually be larger than with 32-bit JVMs. As much as 80% more memory may be required for 64-bit JVMs, due to object references and headers using more memory. - -There are several additional considerations for calculating your memory requirements: - -- **Size of your stored data.** To estimate the size of your stored data, determine first whether you are storing the data in serialized or non-serialized form. In general, the non-serialized form will be the larger of the two. See [Determining Object Serialization Overhead](#topic_psn_5tz_j4) - - Objects in Geode are serialized for storage into partitioned regions and for all distribution activities, including moving data to disk for overflow and persistence. For optimum performance, Geode tries to reduce the number of times an object is serialized and deserialized, so your objects may be stored in serialized or non-serialized form in the cache. - -- **Application object overhead for your data.** When calculating application overhead, make sure to count the key as well as the value, and to count every object if the key and/or value is a composite object. - - The following section "Calculating Application Object Overhead" provides details on how to estimate the memory overhead of the keys and values stored in the cache. - -## <a id="topic_kjx_brz_j4" class="no-quick-link"></a>Calculating Application Object Overhead - -To compute the memory overhead of a Java object, perform the following steps: - -1. **Determine the object header size.** Each Java object has an object header. For a 32-bit JVM, it is 8 bytes. For a 64-bit JVM with a heap less than or equal to 32GB, it is 12 bytes. For a 64-bit JVM with a heap greater than 32GB, it is 16 bytes. -2. **Determine the memory overhead of the fields of the object.** For every instance field (including fields from super classes), add in the field's size. For primitive fields the sizes are: - - 8 for long and double - - 4 for int and float - - 2 for char and short - - 1 for byte and boolean - - For object reference fields, the size is 8 bytes for 64-bit JVM with a heap greater than 32GB. For all other JVMs, use 4 bytes. -3. **Add up the numbers from Step 1 and 2 and round it up to the next multiple of 8.** The result is the memory overhead of that Java object. - -**Java arrays.** To compute the memory overhead of a Java array, you would add the object header (since the array is an object) and a primitive int field that contains its size. Treat each element of the array as if it was an instance field. For example, a byte array of the size 100 bytes would have one object header, one int field, and 100 byte fields. Use the three step process described above to do the computation. - -**Serialized objects.** When computing the memory overhead of a serialized value, remember that the serialized form is stored in a byte array. Therefore, to figure out how many bytes the serialized form contains, compute the memory overhead of a Java byte array of that size and then add in the size of the serialized value wrapper. - -When a value is initially stored in the cache in serialized form, a wrapper around the value is introduced that is kept in memory for the life of that value even if the value is later deserialized. Although this wrapper is only used internally, it does add to the memory footprint. The wrapper is an object with one int field and one object reference. - -If you are using partitioned regions, every value is initially stored in serialized form. For other region types only values that come from a remote member (peers or clients) are initially stored in serialized form. (This is the most common case.) However, if a local operation stores the value in the local JVM's cache, then the value will be stored in object form. A large number of operations can cause a value stored in serialized form to be deserialized. Any operation that needs the object form of the value to be local can cause this deserialization. If such operations are performed, then that value will be stored in object form (with the additional serialized wrapper) and the serialized form becomes garbage. - -**Note:** -An exception to this is if the serialized from is encoded with PDX, then setting `read-serialized` to true will keep the serialized form in the cache. - -See [Determining Object Serialization Overhead](#topic_psn_5tz_j4) for additional information on how to calculate memory usage requirements for storing serialized objects. - -## <a id="topic_exn_2tz_j4" class="no-quick-link"></a>Using Key Storage Optimization - -Keys are stored in object form except for certain classes where the storage of keys is optimized. Key storage is optimized by replacing the entry's object reference to the key with one or two primitive fields on the entry that store the key's data "inline". The following rules apply to determine whether a key is stored "inline": - -- If the key's class is `java.lang.Integer`, `java.lang.Long`, or `java.util.UUID`, then the key is always stored inline. The memory overhead for an inlined Integer or Long key is 0 (zero). The memory overhead for an inlined UUID is 8. -- If the key's class is `java.lang.String`, then the key will be inlined if the string's length is small enough. - - - For ASCII strings whose length is less than 8, the inline memory overhead is 0 (zero). - - For ASCII strings whose length is less than 16, the inline memory overhead is 8. - - For non-ASCII strings whose length is less then 4, the inline memory overhead is 0 (zero). - - For non-ASCII strings whose length is less then 8 the inline memory overhead is 8. - - All other strings are not inlined. - -**When to disable inline key storage.** In some cases, storing keys inline may introduce extra memory or CPU usage. If all of your keys are also referenced from some other object, then it is better to not inline the key. If you frequently ask for the key from the region, then you may want to keep the object form stored in the cache so that you do not need to recreate the object form constantly. Note that the basic operation of checking whether a key is in a region does not require the object form but uses the inline primitive data. - -The key inlining feature can be disabled by specifying the following Geode property upon member startup: - -``` pre --Dgemfire.DISABLE_INLINE_REGION_KEYS=true -``` - -## <a id="topic_ac4_mtz_j4" class="no-quick-link"></a>Measuring Cache Overhead - -This table gives estimates for the cache overhead in a 32-bit JVM. The overhead is required even when an entry is overflowed or persisted to disk. Actual memory use varies based on a number of factors, including the JVM type and the platform you run on. For 64-bit JVMs, the usage will usually be larger than with 32-bit JVMs and may be as much as 80% more. - -<table> -<colgroup> -<col width="50%" /> -<col width="50%" /> -</colgroup> -<thead> -<tr class="header"> -<th>When calculating cache overhead...</th> -<th>You should ...</th> -</tr> -</thead> -<tbody> -<tr class="odd"> -<td>For each region -<div class="note note"> -<b>Note:</b> -<p>Memory consumption for object headers and object references can vary for 64-bit JVMs, different JVM implementations, and different JDK versions.</p> -</div></td> -<td>add 64 bytes per entry</td> -</tr> -<tr class="even"> -<td>And concurrency checking is disabled (it is enabled by default)</td> -<td>subtract 16 bytes per entry -<p>(See <a href="../../developing/distributed_regions/how_region_versioning_works.html#topic_0BDACA590B2C4974AC9C450397FE70B2">Overhead for Consistency Checks</a>.)</p></td> -</tr> -<tr class="odd"> -<td>And statistics are enabled for the region</td> -<td>add 16 bytes per entry</td> -</tr> -<tr class="even"> -<td>And the region is persisted</td> -<td>add 52 bytes per entry</td> -</tr> -<tr class="odd"> -<td>And the region is overflow only</td> -<td>add 44 bytes per entry</td> -</tr> -<tr class="even"> -<td>And the region has an LRU eviction controller</td> -<td>add 16 bytes per entry</td> -</tr> -<tr class="odd"> -<td>And the region has global scope</td> -<td>add 110 bytes per entry</td> -</tr> -<tr class="even"> -<td>And the region has entry expiration configured</td> -<td>add 112 bytes per entry</td> -</tr> -<tr class="odd"> -<td>For each optional user attribute</td> -<td>add 40 bytes per entry plus the memory overhead of the user attribute object</td> -</tr> -</tbody> -</table> - -For indexes used in querying, the overhead varies greatly depending on the type of data you are storing and the type of index you create. You can roughly estimate the overhead for some types of indexes as follows: - -- If the index has a single value per region entry for the indexed expression, the index introduces at most 243 bytes per region entry. An example of this type of index is: `fromClause="/portfolios", indexedExpression="id"`. The maximum of 243 bytes per region entry is reached if each entry has a unique value for the indexed expression. The overhead is reduced if the entries do not have unique index values. -- If each region entry has more than one value for the indexed expression, but no two region entries have the same value for it, then the index introduces at most 236 C + 75 bytes per region entry, where C is the average number of values per region entry for the expression. - -## <a id="topic_i1m_stz_j4" class="no-quick-link"></a>Estimating Management and Monitoring Overhead - -Geode's JMX management and monitoring system contributes to memory overhead and should be accounted for when establishing the memory requirements for your deployment. Specifically, the memory footprint of any processes (such as locators) that are running as JMX managers can increase. - -For each resource in the distributed system that is being managed and monitored by the JMX Manager (for example, each MXBean such as MemberMXBean, RegionMXBean, DiskStoreMXBean, LockServiceMXBean and so on), you should add 10 KB of required memory to the JMX Manager node. - -## <a id="topic_psn_5tz_j4" class="no-quick-link"></a>Determining Object Serialization Overhead - -Geode PDX serialization can provide significant space savings over Java Serializable in addition to better performance. In some cases we have seen savings of up to 65%, but the savings will vary depending on the domain objects. PDX serialization is most likely to provide the most space savings of all available options. DataSerializable is more compact, but it requires that objects are deserialized on access, so that should be taken into account. On the other hand, PDX serializable does not require deserialization for most operations, and because of that, it may provide greater space savings. - -In any case, the kinds and volumes of operations that would be done on the server side should be considered in the context of data serialization, as Geode has to deserialize data for some types of operations (access). For example, if a function invokes a get operation on the server side, the value returned from the get operation will be deserialized in most cases (the only time it will not be deserialized is when PDX serialization is used and the read-serialized attribute is set). The only way to find out the actual overhead is by running tests, and examining the memory usage. - -Some additional serialization guidelines and tips: - -- If you are using compound objects, do not mix using standard Java serialization with with Geode serialization (either DataSerializable or PDX). Standard Java serialization functions correctly when mixed with Geode serialization, but it can end up producing many more serialized bytes. - - To determine if you are using standard Java serialization, specify the `-DDataSerializer.DUMP_SERIALIZED=true` upon process execution. Then check your log for messages of this form: - - ``` pre - DataSerializer Serializing an instance of <className> - ``` - - Any classes list are being serialized with standard Java serialization. You can optimize your serialization by handling those classes in a `PdxSerializer` or a `DataSerializer` or changing the class to be `PdxSerializable` or `DataSerializable`. - -- A simple way to determine the serialized size of an object is to create an instance of that object and then call `DataSerializer.writeObject(obj dataOutput)` where "dataOutput" wraps a `ByteArrayOutputStream`. You can then ask the stream for its size, and it will return the serialized size. Make sure you have configured your `PdxSerializer` and/or `DataSerializer`(s) configured before you calling `writeObject`. - -If you do want to estimate memory usage for PDX serialized data, the following table provides estimated sizes for various types when using PDX serialization: - -| Type | Memory Usage | -|---------------|----------------------------------------------------------------------------------------------------------------------------------------------------| -| boolean | 1 byte | -| byte | 1 byte | -| char | 2 bytes | -| short | 2 bytes | -| int | 4 bytes | -| long | 8 bytes | -| float | 8 bytes | -| String | String.length + 3 bytes | -| Domain Object | 9 bytes (for PDX header) + object serialization length (total all member fields) + 1 to 4 extra bytes (depends on the total size of Domain object) | - -A note of caution-- if the domain object contains many domain objects as member fields, then the memory overhead of PDX serialization can be considerably more than other types of serialization. - -## <a id="topic_d3g_c5z_j4" class="no-quick-link"></a>Calculating Socket Memory Requirements - -Servers always maintain two outgoing connections to each of their peers. So for each peer a server has, there are four total connections: two going out to the peer and two coming in from the peer. - -The server threads that service client requests also communicate with peers to distribute events and forward client requests. If the server's Geode connection property *conserve-sockets* is set to true (the default), these threads use the already-established peer connections for this communication. - -If *conserve-sockets* is false, each thread that services clients establishes two of its own individual connections to its server peers, one to send, and one to receive. Each socket uses a file descriptor, so the number of available sockets is governed by two operating system settings: - -- maximum open files allowed on the system as a whole -- maximum open files allowed for each session - -In servers with many threads servicing clients, if *conserve-sockets* is set to false, the demand for connections can easily overrun the number of available sockets. Even with *conserve-sockets* set to false, you can cap the number of these connections by setting the server's *max-threads* parameter. - -Since each client connection takes one server socket on a thread to handle the connection, and since that server acts as a proxy on partitioned regions to get results, or execute the function service on behalf of the client, for partitioned regions, if conserve sockets is set to false, this also results in a new socket on the server being opened to each peer. Thus N sockets are opened, where N is the number of peers. Large number of clients simultaneously connecting to a large set of peers with a partitioned region with conserve sockets set to false can cause a huge amount of memory to be consumed by socket. Set conserve-sockets to true in these instances. - -**Note:** -There is also JVM overhead for the thread stack for each client connection being processed, set at 256KB or 512KB for most JVMs . On some JVMs you can reduce it to 128KB. You can use the Geode `max-threads` property or the Geode `max-connections` property to limit the number of client threads and thus both thread overhead and socket overhead. - -The following table lists the memory requirements based on connections. - -<table> -<colgroup> -<col width="50%" /> -<col width="50%" /> -</colgroup> -<thead> -<tr class="header"> -<th>Connections</th> -<th>Memory requirements</th> -</tr> -</thead> -<tbody> -<tr class="odd"> -<td>Per socket</td> -<td><p>32,768 /socket (configurable)</p> -<p>Default value per socket should be set to a number > 100 + sizeof (largest object in region) + sizeof (largest key)</p></td> -</tr> -<tr class="even"> -<td>If server (for example if there are clients that connect to it)</td> -<td>= (lesser of max-threads property on server or max-connections)* (socket buffer size +thread overhead for the JVM )</td> -</tr> -<tr class="odd"> -<td>Per member of the distributed system if conserve sockets is set to true</td> -<td>4* number of peers</td> -</tr> -<tr class="even"> -<td>Per member, if conserve sockets is set to false</td> -<td>4 * number of peers hosting that region* number of threads</td> -</tr> -<tr class="odd"> -<td>If member hosts a Partitioned Region, If conserve sockets set to false and it is a Server (this is cumulative with the above)</td> -<td><p>=< max-threads * 2 * number of peers</p> -<div class="note note"> -<b>Note:</b> -<p>it is = 2* current number of clients connected * number of peers. Each connection spawns a thread.</p> -</div></td> -</tr> -<tr class="even"> -<td><strong>Subscription Queues</strong></td> -<td></td> -</tr> -<tr class="odd"> -<td><p>Per Server, depending on whether you limit the queue size. If you do, you can specify the number of megabytes or the number of entries until the queue overflows to disk. When possible, entries on the queue are references to minimize memory impact. The queue consumes memory not only for the key and the entry but also for the client ID/or thread ID as well as for the operation type. Since you can limit the queue to 1 MB, this number is completely configurable and thus there is no simple formula.</p></td> -<td>1 MB +</td> -</tr> -<tr class="even"> -<td><strong>Geode classes and JVM overhead</strong></td> -<td>Roughly 50MB</td> -</tr> -<tr class="odd"> -<td><strong>Thread overhead</strong></td> -<td></td> -</tr> -<tr class="even"> -<td><p>Each concurrent client connection into the a server results in a thread being spawned up to max-threads setting. After that a thread services multiple clients up to max-clients setting.</p></td> -<td>There is a thread stack overhead per connection (at a minimum 256KB to 512 KB, you can set it to smaller to 128KB on many JVMs.)</td> -</tr> -</tbody> -</table> - -<a id="topic_eww_rvz_j4"></a> http://git-wip-us.apache.org/repos/asf/geode-native/blob/ff80a931/geode-docs/reference/topics/non-ascii_strings_in_config_files.html.md.erb ---------------------------------------------------------------------- diff --git a/geode-docs/reference/topics/non-ascii_strings_in_config_files.html.md.erb b/geode-docs/reference/topics/non-ascii_strings_in_config_files.html.md.erb deleted file mode 100644 index 0e2ce3f..0000000 --- a/geode-docs/reference/topics/non-ascii_strings_in_config_files.html.md.erb +++ /dev/null @@ -1,26 +0,0 @@ ---- -title: Using Non-ASCII Strings in Apache Geode Property Files ---- - -You can specify Unicode (non-ASCII) characters in Apache Geode property files by using a `\uXXXX` escape sequence. - -For a supplementary character, you need two escape sequences, one for each of the two UTF-16 code units. The XXXX denotes the 4 hexadecimal digits for the value of the UTF-16 code unit. For example, a properties file might have the following entries: - -``` pre -s1=hello there -s2=\u3053\u3093\u306b\u3061\u306f -``` - -For example, in `gemfire.properties`, you might write: - -``` pre -log-file=my\u00df.log -``` - -to indicate the desired propery definition of `log-file=myÃ.log`. - -If you have edited and saved the file in a non-ASCII encoding, you can convert it to ASCII with the `native2ascii` tool included in your Oracle Java distribution. For example, you might want to do this when editing a properties file in Shift\_JIS, a popular Japanese encoding. - -For more information on internationalization in Java, see [http://www.oracle.com/technetwork/java/javase/tech/intl-139810.html](http://www.oracle.com/technetwork/java/javase/tech/intl-139810.html). - -
