Performance Impact of Proxies in Data Intensive Client-Server Applications
Performance Impact of Proxies in Data Intensive
Client-Server Applications
Michael D.Beynon,Alan Sussman,Joel Saltz
UMIACS and Department of Computer Science
University of Maryland
College Park,MD20742
beynon,als,saltz@https://www.wendangku.net/doc/a515885934.html,
ABSTRACT
Large client-server data intensive applications can place high de-
mands on system and network resources.This is especially true
when the connection between the client and server spans a wide-
area internet link.In this paper,we describe our experience chang-
ing the typical client-server architecture for a class of data inten-
sive applications.We show that given suf?cient common interest
among multiple clients,our enhancements reduce the response time
per-client,the response-time variation and the amount of data sent
across the wide-area link.In addition,we also see a reduction in
server utilization which helps to improve server scalability.
Keywords
Wide-area,Proxy,Caching,Client-Server,Scalability.
1INTRODUCTION
When designed for a client-server environment,image processing
and image browsing applications can place high demands on the
underlying system and network resources.For example,the Mi-
crosoft TerraServer archive of high resolution satellite imagery[18]
currently contains about3.5TeraBytes of data(uncompressed)that
are available for interactive browsing.When interactivity is needed
and the client to server connection spans a wide-area internet con-
nection,the demands on the network can be extremely high.
In this paper we consider the effect of changing the typical
client-server architecture to include a caching proxy server in be-
tween colocated clients and the data server.With the proxy in place
and given suf?cient common interest among multiple clients,typi-
cal proxy bene?ts can be realized.The response time seen by each
client can be reduced and made more deterministic,the amount of
redundant data sent across the wide-area network can be reduced,
and server scalability can be improved by reducing its utilization.
The magnitude of any possible bene?t(or degradation)is directly
related to the amount of common interest among the clients and how
well synchronized it is in time.
LAN
(a)Original
System
LAN
(b)Modi?ed System
Figure1:Architecture example for one remote server and one clus-tered set of clients
2ARCHITECTURE
2.1Original System
The original system is comprised of a server and one or more clients. The server is further decomposed into a single frontend process and one or more backend processes with attached disks.Since the server is designed to run on a parallel machine,the backend processes are intended to each run on a separate node.The application data is declustered across the backend disks.The dissemination model used is request-response(Figure2(a)),where clients send a single multi-dimensional rectangular range query to the frontend process. The frontend reads a batch of queries,and broadcasts them to the backend processes.Given good spatial declustering,most backend processes will have data for a single query on one of their local disks.Each backend process with data for the batch of queries will read the data from the disks,perform computation on the data,and send it directly to the requesting clients.
We want the techniques used to apply for all instances of our class of applications.Toward this goal,we want to avoid data de-pendent operation where possible.We rely completely on the meta-data associated with data blocks and not the data blocks themselves for the Virtual Microscope system modi?cations.This meta-data describes what slide the data is from,focal plane,spatial coordi-nates,etc.If we wanted to allow changes in the server and client to support data block compression,opaque treatment of the data blocks reduces changes needed in the modi?ed system code. 2.2Modi?ed System
The original system was designed primarily for fast data movement in the server.The proposed changes are explicitly for supporting multiple co-located remote clients.
Proxy
The major architectural change is the addition of a proxy as an inter-mediary in between a set of co-located clients and a remote server (Figures1(a)and1(b)).As for any proxy,it will appear to the server as a client,and to the clients as a server.It is possible for such a proxy to perform various functions such as caching,
predictive
(a)Original
System
(b)Modi?ed System
Figure2:Client Query Control Flow prefetching,and computation on the data.For this initial design we only consider caching.
Caching at the proxy provides a bene?t when two properties are present.First,the clients need to be local to the proxy.This re-duces the long latency seen in contacting the remote server to re-solve proxy cache misses.Second,some commonality of interest between the set of clients must exist.This reduces the working set size in the proxy which helps avoid cache over?ow.With both con-ditions satis?ed,the maximum bene?t occurs when only the?rst re-quest for a block of data is not in the proxy cache.
Note that we could also consider caching at the client,which can provide many of the bene?ts we describe for the proxy caching. While this is a valid approach,this work attempts to isolate the case where caching happens in a proxy.
Cache Model Issues
The?rst consideration involves the unit of storage for the cache. The classic options here include variable or uniform sized blocks[5].We chose to use uniform blocks for several reasons. Uniform blocks make the cache replacement decisions simpler, because the space gain for any eviction is the same.Detecting when requests have some commonality is faster with a uniform cache entry size.Given two requests and,the question becomes,is there any overlap?Intersection of rectangles is simple to compute,but deciding quickly how to handle the overlap is the problem.There could be a relatively small amount of overlap,in which case the bene?t of eliminating the redundant data might not be great enough to outweigh the work to detect and decide how to handle it.
Another question is how to handle commonality in requests that are offset temporally.Should be delayed for future requests, with the intention to coalesce them together into a single request? If so,how long should be delayed?This approach may be good for achieving the minimum data redundancy,but it can increase re-sponse time.
Cache Model Design
Each incoming query is translated to a set of queries for individual blocks containing the query result,as seen in Figure2(b).Blocks that are cache misses are immediately requested from the server. Blocks that are cache hits are sent to the client.Pending blocks1 are tagged with this client’s id as another recipient.When blocks
eventually arrive from the server,they are sent to the set of waiting clients.
Uniform blocking helps detect commonality in a passive yet ef-?cient manner.No request is ever delayed in the hope of?nding regions in common with those of another request,yet block-level commonality is exploited.Figure3(a)shows request arriving with an empty cache in the proxy.All blocks for the request are faulted from the server.Consider the case where blocks
have arrived at the proxy,and blocks are pending when re-quest arrives,as shown in Figure3(b).In this case,the proxy faults blocks from the server and sends blocks im-mediately from the cache.Recognizing the commonality between these requests,the client’s id is added to the pending list for blocks .
3WORKLOAD
We instrumented one of the Virtual Microscope clients and captured sets of traces of trained pathologists using the system.The user ex-amined several slides,thoroughly searching each slide for any ab-normality,as they would with a real microscope.We performed tracing for several sessions,and derived an abstract model of user behavior.We present highlights of the detailed model[4]here.
Zoom P(200X)P(50X)
400X0.350.00
0.020.18
100X0.050.45
0.150.08
P(3MB)
0.99
200X0.01
0.92
50X0.30
(b)Choose next request size
Table1:Workload model probability transition matrices
The available magni?cations for our test slide data set ranged from to.Through analysis of the traces,we discovered that the previous magni?cation selected heavily in?uences the mag-ni?cation to be chosen next.Table1(a)shows the probability matrix used for choosing a magni?cation,based on the current magni?ca-tion.
The client generates two request sizes.The larger request size is for the full view screen,which for a default window size is ap-proximately.The smaller request size results from the?ne control buttons in the client that allow for incremental movement in any direction,which generate a request of approximately. Table1(b)describes the probabilities of the next request size,based on the current.Similarly,magni?cation also worked well as a pre-dictor for inter-request time,also known as think time.
4SIMULATION
We simulated the system to quantify the potential bene?ts of using a proxy.Here we present highlights of a more complete simulation study[4].
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Figure4:Client Response Time as No.Clients Increased
We are interested in determining the number of clients that can be supported at varying quality of service levels.To this end,we in-strumented the Virtual Microscope client and server as well as the proxy prototype.From the resulting execution traces on a server with a single backend process,we generated component level per-formance histograms,which are used to?nd representative distribu-tions.These,combined with the workload model,are used to drive a discrete event-driven simulation.For network wide-area(WAN) and local area(LAN)characterizations,we ran micro-benchmarks on our local test machines and a test machine at the San Diego Su-percomputing Center.
One abstraction that was necessary for simulation was to decou-ple cache hits from actual request regions.Requests are modeled in an opaque way,never specifying the spatial coordinates within the slide.Each request is broken into sized blocks,and a Bernoulli trial is used for each block based on the cache hit rate. This allows us to easily consider the effects of different workloads (cache hit rates)while keeping the volume abstract and constant.
4.1Response Time
We consider response time separately for queries resulting in large and small replies in Figures4(a)and4(b),respectively.For both
Cached 01
Empty
(a)Request arrives at time
(b)Request arrives at time
Figure 3:Proxy Cache state as requests arrive
graphs,the mean response time across all clients is shown as we
scale the number of concurrent clients.The system without a proxy is shown as a baseline.The remaining curves are for con?gurations with the proxy turned on,with different cache hit probabilities.For the No Proxy case,the response time increases almost lin-early as the number of clients is increased.The cache hit rate follows the No Proxy baseline very closely,as expected.The only overhead is the constant time for the data to pass through the proxy.The ,and curves all show improvement in the re-sponse time due to the reduction in WAN communication and re-duced server load.It is interesting to note the large reduction in re-sponse time between the and cache hit rates,which in-dicates (as expected)that very good cache hit rates are critical to getting the best performance.For large requests,the ,and con?gurations all somewhat closely follow the baseline No Proxy performance.In contrast,for small requests the cache hit rate response time is approximately half that of the large https://www.wendangku.net/doc/a515885934.html,rger requests cover more cache blocks,so are more likely to include the full latency cost of contacting the server over the WAN.
4.2Utilization
Server utilization is the percentage of time the server is busy,and is shown in Figure 5(a).For the case of proxy cache hits,no blocks will ever be requested from the server,so the utilization is zero.Utilization increases as clients are added to the system until saturation,and then levels off.This maximum utilization is about
.Note this is arti?cially low due to the method of time alloca-tion used in our simulation 2.The absolute values of the utilization should be ignored,and the relative trends used to draw conclusions.Proxy utilization follows the expected inverse trend.For low cache hit rates,the proxy does not have much work to do.When the cache hit rate is higher,the overhead of cache maintenance in-creases,and proxy utilization rises.The cache hit rate curve saturates the proxy at 20clients.Initially we had expected the num-ber of clients that a proxy could handle would be higher,so this low number was surprising.An ef?cient cache lookup scheme is abso-lutely imperative in supporting as many clients as possible with a single proxy.
3
This fast network (155Mbit/sec ATM)was used to approach usability in response
times.Had we used slower wide-area connections,the proxy bene?ts would increase.
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Figure 5:Utilization as No.Clients Increased
(a)Left/Right (odd clients)
(b)Up/Down (even clients)
Figure 6:Sweeping patterns over interesting points
hits will be based on commonality in the actual driver requests.In-teresting regions are modeled as points in the slide,and hard-coded into the driver.When a user pans near an interesting region,there is a high probability a request will be generated.The driver adds noise to requests to avoid multiple clients asking for the same re-gion.In addition,we need to avoid having all the clients scan the slide in the same manner.The driver either sweeps through the slide in an up-down fashion or a left-right fashion as shown in Figure 6,as observed from real users.
5.2Results
We now present a subset of the experiments we ran.In all cases,the client driver was run until a total of requests were issued and sat-is?ed per client.This results in approximately of raw image data being read from the disk by the backend process and
of image data being requested for each client.The client image data size is important,because the cache sizes were chosen to avoid hav-ing everything ?t in cache,thus exercising the replacement policy and biasing temporal commonality.
Figure 7shows separate response time curves for ,,,and clients.For the client case shown in Figure 7(a),the results are as expected.There is no commonality across clients when there is only a single client,so the proxy is only adding overhead by breaking a single query into several block queries,and forcing all reply data to ?ow through the proxy on the way back to the client.This is seen most dramatically for the ?rst query with a proxy,where all data must be faulted from the server.Despite these problems,there are times when improvement is seen over the No Proxy curve.This oc-curs when the blocking of the slide causes extra image data to be re-trieved by the proxy for a given request,and the next request is for a nearby region already in the proxy’s cache.In essence,blocking the data causes some prefetching.Of course,there is a tradeoff in the choice of block size,in that larger blocks will improve the prefetch-ing effect,but will also add to the cost of reading and sending the data.We tried block sizes of ,,,,and
.The block size was empirically found to be a good
overall choice for the data set,workload,and machine and network con?guration used.
The two clients in Figure 7(b)are performing different sweep patterns,and any commonality resulting from the common set of interesting points is scattered over time,thus cache misses are com-mon.Considering clients in Figure 7(c),we introduce explicit
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Figure 7:Mean Response Time as number of clients is increased,64KB Proxy Block Size.Error bars delimit min and max times over all clients.
temporal commonality in the client sets ,and ,from the sweep patterns.In this case,we see the response time curves for both proxy cases are generally at or below the No Proxy case.This trend continues in Figure 7(d)with the introduction of more clients while keeping the same two classes of sweep patterns.Another im-portant observation applies to all cases,where more cache hits re-duces the response time variation as seen by the error bars in the plots.
For all experiments,doubling the size of the cache from to does not seem to make a difference.For most cases,the curves are similar.This is probably due to the working set size being less than or approximately equal to .Further experiments with smaller cache sizes are needed to explore cache size sensitivity.We now consider the effect a proxy has on server utilization.As in the simulation experiments,we expect the reduction of requests that are sent to the server to reduce overall server utilization.Table 2shows server utilization for the same set of experiments.For the single backend process con?guration we used,clients are enough to saturate the server.Addition of the proxy reduces the utilization
Clients No Proxy
40MB
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Request density is de?ned to be the number of requests per unit time.
volume increases by about for each client in the No Proxy con?guration.When a proxy is used,this reduces to about
for both cache sizes.Seeing the same volume decrease for both cache sizes,and the small increase in communication volume as clients are added,indicates that for most cases the?rst request for data results in a cache miss and most subsequent requests are satis-?ed in the cache.Even though all data required by the clients does not?t in the cache,the current working set probably does.More cache statistics are needed to determine if this is the case.If this is true,we should either add more interesting regions to increase the working set size,add more noise to the workload or reduce the cache size to make the experiments more fair and exercise the replacement policy.
6DISCUSSION
We can make several key observations from simulating and building a proxy for the Virtual Microscope system.Better understanding of these issues is important for improving the performance of other applications of this type.
Server Phasing
One major problem that can arise is phasing5at the server.The frontend process reads a batch of requests up to some?xed max-imum number,and broadcasts the query batch to the backend pro-cesses to be satis?ed as a single unit.When completed,the backend processes are then ready to handle the next query batch.
Since the proxy rewrites a single client query into potentially many queries for individual blocks,poor phasing can occur when the set of block queries spans two or more server batches.The server is well suited for large client queries sent directly to the server,but breaks down when used for many small proxy queries.
This problem can be handled in various ways.The protocol could be augmented to include a?ag that asks the frontend to con-tinue reading client queries until the one marked last.Alternatively, we could add a new query packet that can hold more than one multi-dimensional range query,and the proxy would only send one multi-query to the server.
Uniform Cache Block Size
In the?rst proxy design,we wanted all magni?cation levels for a particular block of data to land in the same hash bucket.This would allow the proxy to down-sample cached block data when a request arrives for a lower resolution.Slide data opaqueness is violated,but we wanted to investigate the trade-offs.In this case,the size and number of blocks would vary based on the query magni?cation.
Since Virtual Microscope slides are two-dimensional,the reduc-tion in block size is quite dramatic as magni?cation is reduced.For example,a block size at magni?cation corresponds to a block size at,and at.This results in a huge number of block queries to the server for a large query at low resolution(approx.3072),all to answer a single client query that completely misses the cache.In these cases,caching was ineffective because response time was dominated by the nearly uni-versal need to access the server for a large number of blocks.
This also added a large amount of overhead because of smaller work unit sizes and payload sizes in the server,proxy,and even the network.Without amortizing cost over large work units,the system overhead became signi?cant.Suf?ce to say,performance was a ma-jor problem when using variable block sizes in this manner.The so-lution we employed was to break the slide space into uniform size blocks regardless of resolution.
when initial delays are seen from some data sources.We are taking advantage of spatial locality in a speci?c type of non-relational data.Scrambling is dealing with a different problem on a different type of data.
Broadcast Disks[13]tries to alleviate request-response proto-col problems by pushing commonly used data onto a constantly broadcast circular stream.This requires techniques to decide when a client should wait for the next occurrence of needed data on the “disk”,or request it directly from the server.This work is one ex-treme in handling client-server data needs.The other extreme is unicast request-response,which is what the original Virtual Micro-scope system represents.The proxy version is somewhere in be-tween,utilizing intermediate nodes in the path from the client to the server to reduce redundancy.The use of intermediate nodes is a primary distinction between our work and most related database research.Tradeoffs in using client and server resources have been considered for some time[14].
7CONCLUSION
We have shown how the addition of an intermediary(proxy)in be-tween the clients and server of a particular class of data intensive applications can improve performance.Given suf?cient common-ality among a set of clients local to the proxy,we have demon-strated utility by reducing overall system response time and mak-ing it more deterministic,and increasing server scalability by de-creasing server utilization.In addition,we have reduced the amount of data sent over the wide-area connection between the server and the clients.Even in cases with no inter-client commonality,we see some prefetching improvements for a single client.These bene?ts were achieved without changing the existing client or server appli-cation code.
To be fair,there are cases when commonality between client requests does not exist,or the commonality is so temporally dis-tributed that it cannot be exploited.We plan to follow up this work by investigating techniques for deciding when the use of a proxy will be advantageous.If this can be determined,the proxy could be automatically used for cases where it improves performance,and avoided when it does not.
This entire work assumes read-only browsing of the dataset.We have not dealt with the important problems of cache consistency when allowing updates to the dataset.Future work involves allow-ing such updates to occur.
8ACKNOWLEDGMENTS
We would like to thank Anurag Acharya for many early discussions. We would also like to thank Renato Ferreira and Asmara Afework for their work on the simulation study and prototype servers,clients and drivers.John Davis was very helpful in reading and helping re-vise presentation of this paper.
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The way常见用法
The way 的用法 Ⅰ常见用法： 1)the way+ that 2)the way + in which（最为正式的用法） 3)the way + 省略（最为自然的用法） 举例：I like the way in which he talks. I like the way that he talks. I like the way he talks. Ⅱ习惯用法： 在当代美国英语中，the way用作为副词的对格，“the way+ 从句”实际上相当于一个状语从句来修饰整个句子。 1)The way =as I am talking to you just the way I’d talk to my own child. He did not do it the way his friends did. Most fruits are naturally sweet and we can eat them just the way they are—all we have to do is to clean and peel them. 2）The way= according to the way/ judging from the way The way you answer the question, you are an excellent student. The way most people look at you, you’d think trash man is a monster. 3）The way =how/ how much No one can imagine the way he missed her. 4）The way =because
The way的用法及其含义(二)
The way的用法及其含义（二） 二、the way在句中的语法作用 the way在句中可以作主语、宾语或表语： 1.作主语 The way you are doing it is completely crazy.你这个干法简直发疯。 The way she puts on that accent really irritates me. 她故意操那种口音的样子实在令我恼火。The way she behaved towards him was utterly ruthless. 她对待他真是无情至极。 Words are important, but the way a person stands, folds his or her arms or moves his or her hands can also give us information about his or her feelings. 言语固然重要,但人的站姿,抱臂的方式和手势也回告诉我们他(她)的情感。 2.作宾语 I hate the way she stared at me.我讨厌她盯我看的样子。 We like the way that her hair hangs down.我们喜欢她的头发笔直地垂下来。 You could tell she was foreign by the way she was dressed. 从她的穿著就可以看出她是外国人。 She could not hide her amusement at the way he was dancing. 她见他跳舞的姿势，忍俊不禁。 3.作表语 This is the way the accident happened.这就是事故如何发生的。 Believe it or not, that's the way it is. 信不信由你, 反正事情就是这样。 That's the way I look at it, too. 我也是这么想。 That was the way minority nationalities were treated in old China. 那就是少数民族在旧中
(完整版)the的用法
定冠词the的用法： 定冠词the与指示代词this ,that同源,有“那(这)个”的意思,但较弱,可以和一个名词连用,来表示某个或某些特定的人或东西. (1)特指双方都明白的人或物 Take the medicine.把药吃了. (2)上文提到过的人或事 He bought a house.他买了幢房子. I've been to the house.我去过那幢房子. (3)指世界上独一无二的事物 the sun ,the sky ,the moon, the earth (4)单数名词连用表示一类事物 the dollar 美元 the fox 狐狸 或与形容词或分词连用,表示一类人 the rich 富人 the living 生者 (5)用在序数词和形容词最高级,及形容词等前面 Where do you live?你住在哪? I live on the second floor.我住在二楼. That's the very thing I've been looking for.那正是我要找的东西. (6)与复数名词连用,指整个群体 They are the teachers of this school.(指全体教师) They are teachers of this school.(指部分教师) (7)表示所有,相当于物主代词,用在表示身体部位的名词前 She caught me by the arm.她抓住了我的手臂. (8)用在某些有普通名词构成的国家名称,机关团体,阶级等专有名词前 the People's Republic of China 中华人民共和国 the United States 美国 (9)用在表示乐器的名词前 She plays the piano.她会弹钢琴. (10)用在姓氏的复数名词之前,表示一家人 the Greens 格林一家人(或格林夫妇) (11)用在惯用语中 in the day, in the morning... the day before yesterday, the next morning... in the sky... in the dark... in the end... on the whole, by the way...
“the way+从句”结构的意义及用法
“tｈｅwａｙ+从句”结构的意义及用法 首先让我们来看下面这个句子: Ｒead the foｌloｗｉnｇpassagｅａnd talkａbout ｉt wi ｔh your classmaｔes．Try tｏｔeｌl whaｔyｏu thiｎk ｏf Tom aｎd ｏｆｔhe ｗay the chiｌｄrenｔrｅated ｈim. 在这个句子中，ｔhe waｙ是先行词,后面是省略了关系副词that或in whｉch的定语从句。 下面我们将叙述“the ｗaｙ+从句”结构的用法。 1.tｈe wａy之后，引导定语从句的关系词是tｈat而不是hoｗ,因此，<<现代英语惯用法词典＞＞中所给出的下面两个句子是错误的：Ｔhｉs is ｔｈeｗayｈowｉtｈａppened. This is the way how he ａlwａｙs treats me. 2．在正式语体中,thaｔ可被in which所代替;在非正式语体中，ｔhat则往往省略。由此我们得到theｗay后接定语从句时的三种模式：1) tｈe ｗaｙ＋ｔhａt-从句２）the way +ｉn whiｃh－从句3) the ｗay +从句 例如：Ｔｈe way(in whiｃh ，thａt) ｔhｅｓｅｃomｒade ｓloｏｋａｔｐrobｌems is wrong．这些同志看问题的方法
不对。 Ｔｈｅｗａy(that ,ｉn ｗhiｃh)yoｕ’ｒe doinｇit is comple ｔeｌy crａzy.你这么个干法,简直发疯。 Wｅａdmiｒｅd him for thｅｗay ｉｎｗhｉch he fａｃeｓdiｆficultieｓ． Waｌlａｃe ａｎd Ｄarwiｎｇreed ｏn the way ｉｎwhi ｃh ｄｉfｆｅrｅnt forms ｏf life had ｂegｕn.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 Thｉs is ｔｈe ｗaｙ（tｈａｔ) hｅdｉd it. I lｉkeｄｔhe waｙ(ｔhat) ｓｈeｏｒganized ｔhe ｍeetｉng． 3.theｗay(tｈat)有时可以与hｏw(作“如何”解）通用。例如： That’s tｈe ｗaｙ(tｈaｔ) shｅspoke. = Tｈat’s how shｅspoke.
way 用法
表示“方式”、“方法”，注意以下用法： 1.表示用某种方法或按某种方式，通常用介词in(此介词有时可省略)。如： Do it (in) your own way. 按你自己的方法做吧。 Please do not talk (in) that way. 请不要那样说。 2.表示做某事的方式或方法，其后可接不定式或of doing sth。 如： It’s the best way of studying [to study] English. 这是学习英语的最好方法。 There are different ways to do [of doing] it. 做这事有不同的办法。 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句，但是其后的从句不能由how 来引导。如： 我不喜欢他说话的态度。 正：I don’t like the way he spoke. 正：I don’t like the way that he spoke. 正：I don’t like the way in which he spoke. 误：I don’t like the way how he spoke. 4.注意以下各句the way 的用法： That’s the way (=how) he spoke. 那就是他说话的方式。 Nobody else loves you the way(=as) I do. 没有人像我这样爱你。 The way (=According as) you are studying now, you won’tmake much progress. 根据你现在学习情况来看，你不会有多大的进步。 2007年陕西省高考英语中有这样一道单项填空题： ——I think he is taking an active part insocial work. ——I agree with you_____. A、in a way B、on the way C、by the way D、in the way 此题答案选A。要想弄清为什么选A，而不选其他几项，则要弄清选项中含way的四个短语的不同意义和用法，下面我们就对此作一归纳和小结。 一、in a way的用法 表示：在一定程度上，从某方面说。如： In a way he was right.在某种程度上他是对的。注：in a way也可说成in one way。 二、on the way的用法 1、表示：即将来(去)，就要来(去)。如： Spring is on the way.春天快到了。 I'd better be on my way soon.我最好还是快点儿走。 Radio forecasts said a sixth-grade wind was on the way.无线电预报说将有六级大风。 2、表示：在路上，在行进中。如： He stopped for breakfast on the way.他中途停下吃早点。 We had some good laughs on the way.我们在路上好好笑了一阵子。 3、表示：(婴儿)尚未出生。如： She has two children with another one on the way.她有两个孩子，现在还怀着一个。 She's got five children，and another one is on the way.她已经有5个孩子了，另一个又快生了。 三、by the way的用法
The way的用法及其含义(一)
The way的用法及其含义（一） 有这样一个句子：In 1770 the room was completed the way she wanted. 1770年，这间琥珀屋按照她的要求完成了。 the way在句中的语法作用是什么？其意义如何？在阅读时，学生经常会碰到一些含有the way 的句子，如：No one knows the way he invented the machine. He did not do the experiment the way his teacher told him.等等。他们对the way 的用法和含义比较模糊。在这几个句子中，the way之后的部分都是定语从句。第一句的意思是，“没人知道他是怎样发明这台机器的。”the way的意思相当于how；第二句的意思是，“他没有按照老师说的那样做实验。”the way 的意思相当于as。在In 1770 the room was completed the way she wanted.这句话中，the way也是as的含义。随着现代英语的发展，the way的用法已越来越普遍了。下面，我们从the way的语法作用和意义等方面做一考查和分析： 一、the way作先行词，后接定语从句 以下3种表达都是正确的。例如：“我喜欢她笑的样子。” 1. the way+ in which +从句 I like the way in which she smiles. 2. the way+ that +从句 I like the way that she smiles. 3. the way + 从句(省略了in which或that) I like the way she smiles. 又如：“火灾如何发生的，有好几种说法。” 1. There were several theories about the way in which the fire started. 2. There were several theories about the way that the fire started.
way 的用法
way 的用法 【语境展示】 1. Now I’ll show you how to do the experiment in a different way. 下面我来演示如何用一种不同的方法做这个实验。 2. The teacher had a strange way to make his classes lively and interesting. 这位老师有种奇怪的办法让他的课生动有趣。 3. Can you tell me the best way of working out this problem? 你能告诉我算出这道题的最好方法吗？ 4. I don’t know the way (that / in which) he helped her out. 我不知道他用什么方法帮助她摆脱困境的。 5. The way (that / which) he talked about to solve the problem was difficult to understand. 他所谈到的解决这个问题的方法难以理解。 6. I don’t like the way that / which is being widely used for saving water. 我不喜欢这种正在被广泛使用的节水方法。 7. They did not do it the way we do now. 他们以前的做法和我们现在不一样。 【归纳总结】 ●way作“方法，方式”讲时，如表示“以……方式”，前面常加介词in。如例1； ●way作“方法，方式”讲时，其后可接不定式to do sth.，也可接of doing sth. 作定语，表示做某事的方法。如例2，例3；
the-way-的用法讲解学习
t h e-w a y-的用法
The way 的用法 "the way+从句"结构在英语教科书中出现的频率较高, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或 in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 一.在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮.
way的用法总结大全
way的用法总结大全 way的用法你知道多少，今天给大家带来way的用法，希望能够帮助到大家，下面就和大家分享，来欣赏一下吧。 way的用法总结大全 way的意思 n. 道路,方法,方向,某方面 adv. 远远地，大大地 way用法 way可以用作名词 way的基本意思是“路,道,街,径”,一般用来指具体的“路,道路”,也可指通向某地的“方向”“路线”或做某事所采用的手段,即“方式,方法”。way还可指“习俗,作风”“距离”“附近,周围”“某方面”等。 way作“方法,方式,手段”解时,前面常加介词in。如果way前有this, that等限定词,介词可省略,但如果放在句首,介词则不可省略。
way作“方式,方法”解时,其后可接of v -ing或to- v 作定语,也可接定语从句,引导从句的关系代词或关系副词常可省略。 way用作名词的用法例句 I am on my way to the grocery store.我正在去杂货店的路上。 We lost the way in the dark.我们在黑夜中迷路了。 He asked me the way to London.他问我去伦敦的路。 way可以用作副词 way用作副词时意思是“远远地,大大地”,通常指在程度或距离上有一定的差距。 way back表示“很久以前”。 way用作副词的用法例句 It seems like Im always way too busy with work.我工作总是太忙了。 His ideas were way ahead of his time.他的思想远远超越了他那个时代。 She finished the race way ahead of the other runners.她第一个跑到终点,远远领先于其他选手。 way用法例句
the_way的用法大全教案资料
t h e_w a y的用法大全
The way 在the way+从句中, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或 in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 如果怕弄混淆，下面的可以不看了 另外，在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮. the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的
the way 的用法
The way 的用法 "the way+从句"结构在英语教科书中出现的频率较高, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 一.在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮.
the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的 the way =while/when(表示对比) 9)From that day on, they walked into the classroom carrying defeat on their shoulders the way other students carried textbooks under their arms. 从那天起,其他同学是夹着书本来上课,而他们却带着"失败"的思想负担来上课.
The way的用法及其含义(三)
The way的用法及其含义（三） 三、the way的语义 1. the way=as（像） Please do it the way I’ve told you.请按照我告诉你的那样做。 I'm talking to you just the way I'd talk to a boy of my own.我和你说话就像和自己孩子说话一样。 Plant need water the way they need sun light. 植物需要水就像它们需要阳光一样。 2. the way=how（怎样，多么） No one can imagine the way he misses her.没人能够想象出他是多么想念她！ I want to find out the way a volcano has formed.我想弄清楚火山是怎样形成的。 He was filled with anger at the way he had been treated.他因遭受如此待遇而怒火满腔。That’s the way she speaks.她就是那样讲话的。 3. the way=according as （根据） The way you answer the questions, you must be an excellent student.从你回答问题来看，你一定是名优秀的学生。 The way most people look at you, you'd think a trash man was a monster.从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物。 The way I look at it, it’s not what you do that matters so much.依我看，重要的并不是你做什么。 I might have been his son the way he talked.根据他说话的样子，好像我是他的儿子一样。One would think these men owned the earth the way they behave.他们这样行动，人家竟会以为他们是地球的主人。
way的用法
一．Way：“方式”、“方法” 1.表示用某种方法或按某种方式 Do it (in) your own way. Please do not talk (in) that way. 2.表示做某事的方式或方法 It’s the best way of studying [to study] English.。 There are different ways to do [of doing] it. 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句 正：I don’t like the way he spoke. I don’t like the way that he spoke. I don’t like the way in which he spoke.误：I don’t like the way how he spoke. 4. the way 的从句 That’s the way (=how) he spoke. I know where you are from by the way you pronounce my name. That was the way minority nationalities were treated in old China. Nobody else loves you the way(=as) I do. He did not do it the way his friend did. 二．固定搭配 1. In a/one way：In a way he was right. 2. In the way /get in one’s way I'm afraid your car is in the way， If you are not going to help，at least don't get in the way. You'll have to move－you're in my way. 3. in no way Theory can in no way be separated from practice. 4. On the way (to……) Let’s wait a few moments. He is on the way Spring is on the way. Radio forecasts said a sixth-grade wind was on the way. She has two children with another one on the way. 5. By the way By the way，do you know where Mary lives? 6. By way of Learn English by way of watching US TV series. 8. under way 1. Elbow one’s way He elbowed his way to the front of the queue. 2. shoulder one’s way 3. feel one‘s way 摸索着向前走；We couldn’t see anything in the cave, so we had to feel our way out 4. fight/force one’s way 突破。。。而前进The surrounded soldiers fought their way out. 5.. push/thrust one‘s way（在人群中）挤出一条路He pushed his way through the crowd. 6. wind one’s way 蜿蜒前进 7. lead the way 带路，领路；示范 8. lose one‘s way 迷失方向 9. clear the way 排除障碍，开路迷路 10. make one’s way 前进，行进The team slowly made their way through the jungle.
the way的用法大全
在the way+从句中, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 如果怕弄混淆，下面的可以不看了 另外，在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮. the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的 the way =while/when(表示对比) 9)From that day on, they walked into the classroom carrying defeat on their shoulders the way other students carried textbooks under their arms.
“the-way+从句”结构的意义及用法知识讲解
“the way+从句”结构的意义及用法 首先让我们来看下面这个句子： Read the following passage and talk about it with your classmates. Try to tell what you think of Tom and of the way the children treated him. 在这个句子中，the way是先行词，后面是省略了关系副词that 或in which的定语从句。 下面我们将叙述“the way+从句”结构的用法。 1．the way之后，引导定语从句的关系词是that而不是how,因此，<<现代英语惯用法词典>>中所给出的下面两个句子是错误的：This is the way how it happened. This is the way how he always treats me. 2. 在正式语体中，that可被in which所代替；在非正式语体中，that则往往省略。由此我们得到the way后接定语从句时的三种模式：1) the way +that-从句2) the way +in which-从句3) the way +从句 例如：The way(in which ,that) these comrades look at problems is wrong.这些同志看问题的方法不对。
The way(that ,in which)you’re doing it is completely crazy.你这么个干法，简直发疯。 We admired him for the way in which he faces difficulties. Wallace and Darwin greed on the way in which different forms of life had begun.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 This is the way (that) he did it. I liked the way (that) she organized the meeting. 3.the way(that)有时可以与how(作“如何”解)通用。例如： That’s the way (that) she spoke. = That’s how she spoke. I should like to know the way/how you learned to master the fundamental technique within so short a time. 4．the way的其它用法：以上我们讲的都是用作先行词的the way，下面我们将叙述它的一些用法。
定冠词the的12种用法
定冠词the的12种用法 定冠词the 的12 种用法，全知道?快来一起学习吧。下面就和大家分享，来欣赏一下吧。 定冠词the 的12 种用法，全知道? 定冠词the用在各种名词前面，目的是对这个名词做个记号，表示它的特指属性。所以在词汇表中，定冠词the 的词义是“这个，那个，这些，那些”，可见，the 即可以放在可数名词前，也可以修饰不可数名词，the 后面的名词可以是单数，也可以是复数。 定冠词的基本用法： (1) 表示对某人、某物进行特指，所谓的特指就是“不是别的，就是那个!”如： The girl with a red cap is Susan. 戴了个红帽子的女孩是苏珊。 (2) 一旦用到the，表示谈话的俩人都知道说的谁、说的啥。如：
The dog is sick. 狗狗病了。(双方都知道是哪一只狗) (3) 前面提到过的，后文又提到。如： There is a cat in the tree.Thecat is black. 树上有一只猫，猫是黑色的。 (4) 表示世界上唯一的事物。如： The Great Wall is a wonder.万里长城是个奇迹。(5) 方位名词前。如： thenorth of the Yangtze River 长江以北地区 (6) 在序数词和形容词最高级的前面。如： Who is the first?谁第一个? Sam is the tallest.山姆最高。 但是不能认为，最高级前必须加the，如： My best friend. 我最好的朋友。 (7) 在乐器前。如： play the flute 吹笛子
Way的用法
Way用法 A:I think you should phone Jenny and say sorry to her. B:_______. It was her fault. A. No way B. Not possible C. No chance D. Not at all 说明：正确答案是A. No way，意思是“别想！没门！决不！” 我认为你应该打电话给珍妮并向她道歉。 没门！这是她的错。 再看两个关于no way的例句： （1）Give up our tea break? NO way! 让我们放弃喝茶的休息时间？没门儿！ （2）No way will I go on working for that boss. 我决不再给那个老板干了。 way一词含义丰富，由它构成的短语用法也很灵活。为了便于同学们掌握和用好它，现结合实例将其用法归纳如下： 一、way的含义 1. 路线
He asked me the way to London. 他问我去伦敦的路。 We had to pick our way along the muddy track. 我们不得不在泥泞的小道上择路而行。 2. （沿某）方向 Look this way, please. 请往这边看。 Kindly step this way, ladies and gentlemen. 女士们、先生们，请这边走。 Look both ways before crossing the road. 过马路前向两边看一看。 Make sure that the sign is right way up. 一定要把符号的上下弄对。 3. 道、路、街，常用以构成复合词 a highway（公路），a waterway（水路），a railway（铁路），wayside（路边）
way与time的特殊用法
way/time的特殊用法 1、当先行词是way意思为”方式.方法”的时候,引导定语从句的关系词有下列3种形式： Way在从句中做宾语 The way that / which he explained to us is quite simple. Way在从句中做状语 The way t hat /in which he explained the sentence to us is quite simple. 2、当先行词是time时,若time表示次数时,应用关系代词that引导定语从句,that可以省略; 若time表示”一段时间”讲时,应用关系副词when或介词at/during + which引导定语从句 1.Is this factory _______ we visited last year? 2.Is this the factory-------we visited last year? A. where B in which C the one D which 3. This is the last time _________ I shall give you a lesson. A. when B that C which D in which 4.I don’t like the way ________ you laugh at her. A . that B on which C which D as 5.He didn’t understand the wa y ________ I worked out the problem. A which B in which C where D what 6.I could hardly remember how many times----I’ve failed. A that B which C in which D when 7.This is the second time--------the president has visited the country. A which B where C that D in which 8.This was at a time------there were no televisions, no computers or radios. A what B when C which D that